Filed Pursuant to Rule 424(b)(3)
 
                                                     Registration No. 333-121762
 
PROSPECTUS
 
                     (DIAMOND OFFSHORE DRILLING, INC. LOGO)
 
                        DIAMOND OFFSHORE DRILLING, INC.
 
                                  $250,000,000
 
                       OFFER TO EXCHANGE ALL OUTSTANDING
                    5.15% SENIOR NOTES DUE SEPTEMBER 1, 2014
                                      FOR
                    5.15% SENIOR NOTES DUE SEPTEMBER 1, 2014
                  REGISTERED UNDER THE SECURITIES ACT OF 1933
 
     We are offering to exchange our outstanding notes described above for the
new, registered notes described above. In this prospectus we refer to the
outstanding notes as the "old notes" and our new notes as the "registered
notes," and we refer to the old notes and the registered notes, together, as the
"notes." The form and terms of the registered notes are substantially identical
in all material respects to the form and terms of the old notes, except for
transfer restrictions, registration rights and additional interest payment
provisions relating only to the old notes. We do not intend to apply to have any
notes listed on any securities exchange or automated quotation system and there
may be no active trading market for them.
 
EXCHANGE OFFER
 
     - The exchange offer expires at 5:00 P.M., New York City time, on March 14,
       2005, unless extended. Whether or not the exchange offer is extended, the
       time at which it ultimately expires is referred to in this prospectus as
       the time of expiration.
 
     - All old notes that are validly tendered and not validly withdrawn will be
       exchanged.
 
     - Tenders of old notes in the exchange offer may be withdrawn at any time
       prior to the time of expiration.
 
     - The exchange offer is subject to customary conditions, including that the
       exchange offer not violate any applicable law, regulation or
       interpretation of the staff of the Securities and Exchange Commission or
       be prohibited or impaired by any action or proceeding that has been
       instituted or threatened with respect to the exchange offer.
 
     - We will not receive any cash proceeds from the exchange offer.
 
REGISTERED NOTES
 
     - We will pay interest on the notes on March 1 and September 1 of each
       year. The first such payment will be made on March 1, 2005. We have the
       option to redeem all or a portion of the registered notes at any time at
       the redemption prices set forth in this prospectus.
 
     YOU SHOULD CAREFULLY CONSIDER THE "RISK FACTORS" BEGINNING ON PAGE 8 OF
THIS PROSPECTUS.
 
     NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS
PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.
 
               The date of this prospectus is February 11, 2005.

 
                      WHERE YOU CAN FIND MORE INFORMATION
 
     We have filed with the Securities and Exchange Commission, or the SEC, a
registration statement on Form S-4 under the Securities Act of 1933, as amended,
or the Securities Act, relating to the exchange offer. That registration
statement includes important business and financial information about us that is
not included in or delivered with this prospectus. This prospectus does not
contain all of the information included in the registration statement. That
information is available from us without charge to holders of the old notes.
 
     We are subject to the informational requirements of the Securities Exchange
Act of 1934, as amended, or the Exchange Act, and accordingly file annual,
quarterly and current reports, proxy statements and other information with the
SEC. You may read and copy the registration statement and the information we
file with the SEC at the public reference facilities maintained by the SEC at
450 Fifth Street, N.W., Washington, D.C. 20549. Please call the SEC at
1-800-SEC-0330 for further information on the operation of the public reference
rooms. Our SEC filings are also available to the public from the SEC's Internet
site at http://www.sec.gov or from our Internet site at
http://www.diamondoffshore.com. However, the information on our Internet site
does not constitute a part of this prospectus.
 
     The SEC allows us to "incorporate by reference" into this prospectus
information we file with the SEC, which means that we can disclose important
information to you by referring to the documents containing that information.
The information incorporated by reference is considered to be a part of this
prospectus. Information that we file later with the SEC that is deemed
incorporated by reference into this prospectus (but not information filed with
or furnished to the SEC that is not deemed incorporated) will automatically
update and supersede information previously included.
 
     We are incorporating by reference into this prospectus the documents listed
below and any subsequent filings we make with the SEC under Sections 13(a),
13(c), 14 or 15(d) of the Exchange Act (excluding information deemed to be
furnished and not filed with the SEC) until the offering made by this prospectus
is completed:
 
     - Our annual report on Form 10-K for the fiscal year ended December 31,
       2003;
 
     - Our proxy statement on Schedule 14A filed March 29, 2004;
 
     - Our quarterly reports on Form 10-Q for our fiscal quarters ended March
       31, 2004, June 30, 2004 and September 30, 2004; and
 
     - Our current reports on Form 8-K filed with the SEC on August 25, 2004,
       August 27, 2004, September 1, 2004, September 16, 2004, September 21,
       2004, October 1, 2004, October 18, 2004, January 10, 2005 and February 8,
       2005.
 
     You may request a copy of these filings at no cost (other than an exhibit
to these filings, unless we have specifically incorporated that exhibit by
reference into the filing), by writing or telephoning us at the following
address or telephone number:
 
     Diamond Offshore Drilling, Inc.
     15415 Katy Freeway, Suite 100
     Houston, Texas 77094
     Attention: Investor Relations
     Telephone: (281) 492-5300.
 
     IN ORDER TO OBTAIN DELIVERY OF ANY FILINGS OR OTHER DOCUMENTS FROM US ON A
TIMELY BASIS AND BEFORE YOU MAKE AN INVESTMENT DECISION WITH RESPECT TO THE
EXCHANGE OFFER, YOU MUST DELIVER YOUR REQUEST SO THAT WE RECEIVE IT NO LATER
THAN FIVE BUSINESS DAYS BEFORE YOU MAKE YOUR INVESTMENT DECISION AND, IN ANY
EVENT, NO LATER THAN FIVE BUSINESS DAYS BEFORE THE TIME OF EXPIRATION.
 
                                        i

 
                               PROSPECTUS SUMMARY
 
     The following summary is qualified in its entirety by the more detailed
information included elsewhere in or incorporated by reference into this
prospectus. Because this is a summary, it does not contain all the information
that may be important to you. You should carefully read the entire prospectus,
as well as the information incorporated by reference, before making an
investment decision. When used in this prospectus, the terms "Diamond Offshore,"
"we," "our company," "our" and "us" refer to Diamond Offshore Drilling, Inc., a
Delaware corporation, and its consolidated subsidiaries, unless otherwise
specified.
 
                        DIAMOND OFFSHORE DRILLING, INC.
 
     We are a leading global offshore oil and gas drilling contractor. Our
fleet, which is comprised of 30 semisubmersible rigs, 14 jack-up rigs and one
drillship, is one of the world's largest.
 
     We drill in the waters of North America, South America, Europe, Africa,
Asia and Australia. We offer comprehensive drilling services to the global
energy industry.
 
     Our principal executive offices are located at 15415 Katy Freeway, Houston,
Texas 77094, and our telephone number at that location is (281) 492-5300.
 
                               THE EXCHANGE OFFER
 
     On August 27, 2004, Diamond Offshore Drilling, Inc. issued $250.0 million
aggregate principal amount of its 5.15% senior notes due September 1, 2014, in a
transaction exempt from registration under the Securities Act. We refer to the
issuance of the old notes in this prospectus as the "original issuance."
 
     At the time of the original issuance, we entered into an agreement in which
we agreed to register new notes, with substantially the same form and terms as
the old notes, and to offer to exchange the registered notes for the old notes.
We refer to this agreement in this prospectus as the "registration rights
agreement."
 
     If (but only if) you are eligible to exchange your old notes for registered
notes and you satisfy the conditions set forth below under "-- Resales of the
Registered Notes", we believe that the registered notes issued to you in the
exchange offer may be resold by you without compliance with the registration and
prospectus delivery provisions of the Securities Act. You should read the
discussions under the headings "The Exchange Offer" and "Description of the
Registered Notes" for further information regarding the registered notes.
 
Registration Rights
Agreement.....................   Under the registration rights agreement, we are
                                 obligated to offer to exchange the old notes
                                 for registered notes with terms substantially
                                 identical in all material respects to the old
                                 notes. The exchange offer is intended to
                                 satisfy that obligation. After the exchange
                                 offer is complete, except as set forth in the
                                 next paragraph, you will no longer be entitled
                                 to any exchange or registration rights with
                                 respect to your old notes.
 
                                 The registration rights agreement requires us
                                 to file a registration statement for a
                                 continuous "shelf" offering in accordance with
                                 Rule 415 under the Securities Act for your
                                 benefit if you would not receive freely
                                 transferable registered notes in the exchange
                                 offer as a result of a change in existing SEC
                                 interpretations, if the exchange offer has not
                                 been completed by April 9, 2005 or if you are
                                 ineligible to participate in the exchange offer
                                 and you timely notify us that you wish to have
                                 your old notes registered under the Securities
                                 Act. See "The Exchange Offer -- Purpose and
                                 Effect -- Registration Rights."
 
                                        1

 
The Exchange Offer............   Diamond Offshore Drilling, Inc. is offering to
                                 exchange $1,000 principal amount of its 5.15%
                                 senior notes due 2014, which have been
                                 registered under the Securities Act, for each
                                 $1,000 principal amount of its unregistered
                                 5.15% senior notes due 2014 that were issued in
                                 the original issuance.
 
                                 In order to be exchanged, an old note must be
                                 validly tendered and accepted. All old notes
                                 that are validly tendered and not validly
                                 withdrawn will be accepted and exchanged.
 
                                 As of this date, $250.0 million aggregate
                                 principal amount of notes are outstanding.
 
                                 We will issue the registered notes promptly
                                 after the time of expiration.
 
Resales of the Registered
Notes.........................   Except as described below, we believe that the
                                 registered notes to be issued in the exchange
                                 offer may be offered for resale, resold and
                                 otherwise transferred by you without compliance
                                 with the registration provisions of the
                                 Securities Act if (but only if) you meet the
                                 following conditions:
 
                                 (1) you are not our affiliate, as that term is
                                 defined in Rule 405 under the Securities Act;
 
                                 (2) if you are a broker-dealer, you acquired
                                 the old notes which you seek to exchange for
                                 registered notes as a result of market making
                                 or other trading activities and not directly
                                 from us and you comply with the prospectus
                                 delivery requirements of the Securities Act;
 
                                 (3) the registered notes are acquired by you in
                                 the ordinary course of your business;
 
                                 (4) you are not engaging in and do not intend
                                 to engage in a distribution of the registered
                                 notes; and
 
                                 (5) you do not have an arrangement or
                                 understanding with any person to participate in
                                 the distribution of the registered notes.
 
                                 Our belief is based on interpretations by the
                                 staff of the SEC, as set forth in no-action
                                 letters issued to third parties unrelated to
                                 us. The staff has not considered the exchange
                                 offer in the context of a no-action letter, and
                                 we cannot assure you that the staff would make
                                 a similar determination with respect to the
                                 exchange offer.
 
                                 If you do not meet the above conditions, you
                                 may not participate in the exchange offer or
                                 sell, transfer or otherwise dispose of any old
                                 notes unless (i) they have been registered for
                                 resale by you under the Securities Act and you
                                 deliver a "resale" prospectus meeting the
                                 requirements of the Securities Act or (ii) you
                                 sell, transfer or otherwise dispose of the
                                 notes in accordance with an applicable
                                 exemption from the registration requirements of
                                 the Securities Act.
 
                                 Any broker-dealer that acquired old notes as a
                                 result of market-making activities or other
                                 trading activities, and receives registered
                                 notes for its own account in exchange for those
                                 old notes,
 
                                        2

 
                                 must acknowledge that it will deliver a
                                 prospectus in connection with any resale of the
                                 registered notes. See "Plan of Distribution." A
                                 broker-dealer may use this prospectus for an
                                 offer to resell or to otherwise transfer those
                                 registered notes for a period of 180 days after
                                 the time of expiration.
 
Expiration Date...............   The exchange offer will expire at the time of
                                 expiration, which is 5:00 P.M., New York City
                                 time, on March 14, 2005, unless we decide to
                                 extend the exchange offer.
 
Conditions to the Exchange
Offer.........................   The exchange offer is subject to customary
                                 conditions, including that the exchange offer
                                 would not violate any applicable law,
                                 regulation or interpretation of the staff of
                                 the SEC or be prohibited or impaired by any
                                 action or proceeding that has been instituted
                                 or threatened with respect to the exchange
                                 offer. In addition, we will not be obligated to
                                 accept for exchange the old notes of any holder
                                 that has not made to us the representations
                                 described below under "Procedures for Tendering
                                 Old Notes Held in the Form of Book-Entry
                                 Interests." See "The Exchange
                                 Offer -- Conditions."
 
Procedures for Tendering Old
Notes Held in the Form of
Book-Entry Interests..........   The old notes were issued as global notes in
                                 fully registered form without interest coupons.
                                 Beneficial interests in the old notes held by
                                 direct or indirect participants in The
                                 Depository Trust Company, or DTC, are shown on,
                                 and transfers of those interests are effected
                                 only through, records maintained in book-entry
                                 form by DTC with respect to its participants.
 
                                 If you hold old notes in the form of book-entry
                                 interests and you wish to tender your old notes
                                 for exchange pursuant to the exchange offer,
                                 you must transmit to the exchange agent prior
                                 to the time of expiration of the exchange offer
                                 either:
 
                                 - a written or facsimile copy of a properly
                                   completed and duly executed letter of
                                   transmittal for your notes, including all
                                   other documents required by the letter of
                                   transmittal, at the address set forth on the
                                   cover page of the letter of transmittal; or
 
                                 - a computer-generated message transmitted by
                                   means of DTC's Automated Tender Offer Program
                                   system and received by the exchange agent and
                                   forming a part of a confirmation of book-
                                   entry transfer, in which you acknowledge and
                                   agree to be bound by the terms of the letter
                                   of transmittal for your notes.
 
                                 The exchange agent must also receive prior to
                                 the time of expiration of the exchange offer
                                 either:
 
                                 - a timely confirmation of book-entry transfer
                                   of your old notes into the exchange agent's
                                   account at DTC pursuant to the procedure for
                                   book-entry transfers described in this
                                   prospectus under the heading "The Exchange
                                   Offer -- Book-Entry Transfer;" or
 
                                 - the documents necessary for compliance with
                                   the guaranteed delivery procedures described
                                   below.
 
                                        3

 
                                 A letter of transmittal for your notes
                                 accompanies this prospectus. By executing the
                                 letter of transmittal for your notes or
                                 delivering a computer-generated message through
                                 DTC's Automated Tender Offer Program system,
                                 you will represent to us that, among other
                                 things:
 
                                 - you are not an affiliate of ours;
 
                                 - you are not a broker-dealer that acquired the
                                   old notes that you are sending to us directly
                                   from us;
 
                                 - the registered notes to be acquired by you in
                                   the exchange offer are being acquired by you
                                   in the ordinary course of your business;
 
                                 - you are not engaging in and do not intend to
                                   engage in a distribution of the registered
                                   notes; and
 
                                 - you do not have an arrangement or
                                   understanding with any person to participate
                                   in the distribution of the registered notes.
 
Procedures for Tendering
Certificated Old Notes........   If you are a holder of book-entry interests in
                                 the old notes, you are entitled to receive, in
                                 limited circumstances, in exchange for your
                                 book-entry interests, certificated notes which
                                 are in equal principal amounts to your
                                 book-entry interests. See "Description of the
                                 Registered Notes -- Form, Denomination,
                                 Transfer, Exchange and Book-Entry
                                 Procedures -- Exchanges of Book-Entry Notes for
                                 Certificated Notes." If you acquire
                                 certificated old notes prior to the expiration
                                 of the exchange offer, you must tender your
                                 certificated old notes in accordance with the
                                 procedures described in this prospectus under
                                 the heading "The Exchange Offer -- Procedures
                                 for Tendering -- Certificated Old Notes."
 
Special Procedures for
Beneficial Owners.............   If you are the beneficial owner of old notes
                                 and they are registered in the name of a
                                 broker, dealer, commercial bank, trust company
                                 or other nominee and you wish to tender your
                                 old notes, you should contact the registered
                                 holder promptly and instruct the registered
                                 holder to tender on your behalf. If you wish to
                                 tender on your own behalf, you must, prior to
                                 completing and executing the letter of
                                 transmittal for your notes and delivering your
                                 old notes, either make appropriate arrangements
                                 to register ownership of the old notes in your
                                 name or obtain a properly completed bond power
                                 from the registered holder. The transfer of
                                 registered ownership may take considerable
                                 time. See "The Exchange Offer -- Procedures for
                                 Tendering -- Procedures Applicable to All
                                 Holders."
 
Guaranteed Delivery
Procedures....................   If you wish to tender your old notes in the
                                 exchange offer and:
 
                                 (1) they are not immediately available;
 
                                 (2) time will not permit your old notes or
                                 other required documents to reach the exchange
                                 agent before the expiration of the exchange
                                 offer; or
 
                                        4

 
                                 (3) you cannot complete the procedure for
                                 book-entry transfer on a timely basis,
 
                                 you may tender your old notes in accordance
                                 with the guaranteed delivery procedures set
                                 forth in "The Exchange Offer -- Procedures for
                                 Tendering -- Guaranteed Delivery Procedures."
 
Acceptance of Old Notes and
Delivery of Registered
Notes.........................   Except under the circumstances described above
                                 under "Conditions to the Exchange Offer," we
                                 will accept for exchange any and all old notes
                                 which are properly tendered and not withdrawn
                                 prior to the time of expiration. The registered
                                 notes to be issued to you in exchange offer
                                 will be delivered promptly following the time
                                 of expiration. See "The Exchange Offer -- Terms
                                 of the Exchange Offer."
 
Withdrawal....................   You may withdraw the tender of your old notes
                                 at any time prior to the time of expiration. We
                                 will return to you any old notes not accepted
                                 for exchange for any reason without expense to
                                 you promptly after withdrawal, rejection of
                                 tender or termination of the exchange offer.
 
Exchange Agent................   JPMorgan Chase Bank, N.A. is serving as the
                                 exchange agent in connection with the exchange
                                 offer.
 
Consequences of Failure to
Exchange......................   If you do not participate in the exchange offer
                                 for your old notes, upon completion of the
                                 exchange offer, the liquidity of the market for
                                 your old notes could be adversely affected. See
                                 "The Exchange Offer -- Consequences of Failure
                                 to Exchange."
 
United States Federal Income
Tax Consequences of the
Exchange Offer................   The exchange of old notes for registered notes
                                 will not be a taxable event for United States
                                 federal income tax purposes. See "Certain
                                 United States Federal Income Tax Consequences."
 
                              THE REGISTERED NOTES
 
Issuer........................   Diamond Offshore Drilling, Inc.
 
Registered Notes..............   $250,000,000 aggregate principal amount of
                                 5.15% Senior Notes due 2014 registered under
                                 the Securities Act.
 
Maturity Date.................   September 1, 2014.
 
Interest......................   5.15% per year on the principal amount, payable
                                 semiannually in arrears on March 1 and
                                 September 1 of each year, beginning March 1,
                                 2005. Interest will accrue from August 27,
                                 2004, the date of the original issuance.
 
Ranking.......................   The registered notes will be unsecured and
                                 unsubordinated obligations and will rank equal
                                 in right of payment to all our existing and
                                 future unsecured and unsubordinated
                                 indebtedness. However, the registered notes
                                 will be effectively subordinated to all
                                 existing and future obligations of our
                                 subsidiaries. As of September 30, 2004, Diamond
                                 Offshore Drilling, Inc. had approximately
                                 $1,176.6 million of total indebtedness
                                 outstanding.
 
                                        5

 
                                 As of September 30, 2004, our subsidiaries had
                                 approximately $24.8 million of outstanding
                                 obligations.
 
Sinking Fund..................   None.
 
Redemption of Registered Notes
at Our Option.................   We may redeem all or a portion of the
                                 registered notes for cash at any time or from
                                 time to time, on at least 15 days but not more
                                 than 60 days prior written notice, at a
                                 redemption price equal to the greater of (1)
                                 100% of the principal amount of the registered
                                 notes to be redeemed or (2) the sum of the
                                 present values of the principal amount of the
                                 registered notes to be redeemed and the
                                 remaining scheduled payments of interest
                                 thereon from the redemption date to the
                                 maturity date of the registered notes to be
                                 redeemed (excluding interest accrued to the
                                 redemption date), discounted from their
                                 respective scheduled payment dates to the
                                 redemption date on a semiannual basis at the
                                 specified treasury rate plus 20 basis points,
                                 plus, in either case, accrued and unpaid
                                 interest on the principal amount of the
                                 registered notes redeemed to the date of
                                 redemption. See "Description of the Registered
                                 Notes -- Optional Redemption."
 
Certain Covenants.............   The indenture governing the registered notes
                                 contains covenants that limit, among other
                                 things, subject to certain exceptions, our
                                 ability to:
 
                                 - consolidate with or merge into another entity
                                   or convey or transfer our properties and
                                   assets substantially as a whole;
 
                                 - create liens; and
 
                                 - enter into a sale and lease-back transaction
                                   covering any drilling rig or drillship. See
                                   "Description of the Registered Notes --
                                   Consolidation, Merger, Sale or Conveyance"
                                   and "Description of the Registered
                                   Notes -- Covenants."
 
Use of Proceeds...............   We will not receive any cash proceeds upon
                                 completion of the exchange offer. See "Use of
                                 Proceeds."
 
Form of Registered Notes......   The registered notes will be issued in
                                 book-entry form and will be represented by one
                                 or more permanent global certificates deposited
                                 with a custodian for and registered in the name
                                 of a nominee of DTC in New York, New York.
                                 Beneficial interests in any such securities
                                 will be shown on, and transfers will be
                                 effected only through, records maintained by
                                 DTC and its direct and indirect participants
                                 and any such interest may not be exchanged for
                                 certificated securities, except in limited
                                 circumstances. See "Description of the
                                 Registered Notes -- Form, Denomination,
                                 Transfer, Exchange and Book-Entry Procedures."
 
Registration Rights...........   We may be required to provide a shelf
                                 registration statement to cover resales of the
                                 old notes under certain circumstances. If we
                                 fail to satisfy these obligations, we may be
                                 required to pay you liquidated damages. See
                                 "The Exchange Offer -- Purpose and
                                 Effect -- Registration Rights."
 
                                        6

 
Risk Factors..................   You should carefully consider the specific
                                 factors set forth under "Risk Factors," as well
                                 as the other information and data included
                                 elsewhere or incorporated by reference in this
                                 prospectus, before making an investment
                                 decision.
 
                              RECENT DEVELOPMENTS
 
     Ocean Endeavor Upgrade.  In January 2005, we announced a major upgrade of
our Victory-class semisubmersible, the Ocean Endeavor, for ultra-deepwater
service. The modernized rig will be designed to operate in up to 8,000 feet of
water at an estimated upgrade cost of approximately $250 million. The Ocean
Endeavor will be mobilized to a shipyard in Singapore where work is scheduled to
commence in the second quarter of 2005. We expect delivery of the upgraded rig
in approximately two years.
 
     Fourth Quarter Financial Results.  On February 9, 2005, we announced our
financial results for our fourth quarter of 2004 and for the year ended December
31, 2004. We reported net income for the fourth quarter of 2004 of $11.3
million, or $0.09 per share on a diluted basis, compared with net income of $1.3
million, or $0.01 per share on a diluted basis, in the fourth quarter of 2003.
We reported revenue of $237.3 million for the fourth quarter of 2004, compared
with revenue of $187.7 million for the fourth quarter of 2003.
 
     For the year ended December 31, 2004, we reported a net loss of $7.2
million, or $0.06 per share on a diluted basis, compared with a net loss of
$48.4 million, or $0.37 per share on a diluted basis, for the year ended
December 31, 2003. We reported revenue of $814.7 million for the year ended
December 31, 2004, compared with revenue of $680.9 million for the year 2003.
 
     During the fourth quarter of 2004, we recognized an $11.4 million gain in
other income resulting from the settlement of a lawsuit against an equipment
manufacturer, which was offset by $8.6 million in reactivation costs and
operating expense to bring our mid-water semisubmersible Ocean Voyager out of
cold stack and $3.4 million in charges related to a combination of storm damage
and higher operating costs due to the relocation of the Ocean Vanguard to
Norway.
 
     Additional information concerning our historical results of operations is
contained in our Annual Report on Form 10-K for the fiscal year ended December
31, 2003 and our Quarterly Reports on Form 10-Q for the fiscal quarters ended
March 31, 2004, June 30, 2004 and September 30, 2004, which documents are
incorporated by reference into this prospectus.
 
                                        7

 
                                  RISK FACTORS
 
     An investment in the notes involves a high degree of risk. In considering
whether to participate in the exchange offer, you should consider carefully the
following matters, in addition to the other information included or incorporated
by reference in this prospectus.
 
RISKS RELATING TO OUR BUSINESS
 
  OUR BUSINESS DEPENDS ON THE LEVEL OF ACTIVITY IN THE OIL AND GAS INDUSTRY,
  WHICH IS SIGNIFICANTLY AFFECTED BY VOLATILE OIL AND GAS PRICES.
 
     Our business depends on the level of activity in offshore oil and gas
exploration, development and production in markets worldwide. Oil and gas
prices, market expectations of potential changes in these prices and a variety
of political and economic factors significantly affect this level of activity.
Oil and gas prices are extremely volatile and are affected by numerous factors,
including:
 
     - the political environment of oil-producing regions;
 
     - worldwide demand for oil and gas;
 
     - the ability of the Organization of Petroleum Exporting Countries,
       commonly called OPEC, to set and maintain production levels and pricing;
 
     - the level of production in non-OPEC countries;
 
     - the policies of the various governments regarding exploration and
       development of their oil and gas reserves; and
 
     - advances in exploration and development technology.
 
  OUR INDUSTRY IS HIGHLY COMPETITIVE AND CYCLICAL, WITH INTENSE PRICE
  COMPETITION.
 
     The offshore contract drilling industry is highly competitive with numerous
industry participants, none of which at the present time has a dominant market
share. Some of our competitors may have greater resources than we do.
 
     Drilling contracts are traditionally awarded on a competitive bid basis.
Intense price competition is often the primary factor in determining which
qualified contractor is awarded a job, although rig availability and the quality
and technical capability of service and equipment may also be considered.
 
     Our industry has historically been cyclical. There have been periods of
high demand, short rig supply and high dayrates, followed by periods of lower
demand, excess rig supply and low dayrates. Periods of excess rig supply
intensify the competition in the industry and often result in rigs being idle
for long periods of time. Although oil and natural gas prices are currently
significantly above historical averages, customer demand and contract pricing
for various classes of equipment within the offshore drilling industry have not
matched these increases due to uncertainty among oil producers as to whether the
high level of product prices would continue.
 
  OUR DRILLING CONTRACTS MAY BE TERMINATED DUE TO EVENTS BEYOND OUR CONTROL.
 
     Our customers may terminate some of our term drilling contracts if the
drilling unit is destroyed or lost or if drilling operations are suspended for a
specified period of time as a result of a breakdown of major equipment or, in
some cases, due to other events beyond the control of either party. In addition,
some of our drilling contracts permit the customer to terminate the contract
after specified notice periods by tendering contractually specified termination
amounts. During depressed market conditions, our customers may also seek
renegotiation of firm drilling contracts to reduce their obligations.
 
                                        8

 
  RIG CONVERSIONS, UPGRADES OR NEWBUILDS MAY BE SUBJECT TO DELAYS AND COST
  OVERRUNS.
 
     From time to time we may undertake to add new capacity through conversions
or upgrades to rigs or through new construction. These projects are subject to
risks of delay or cost overruns inherent in any large construction project
resulting from numerous factors, including the following:
 
     - shortages of equipment, materials or skilled labor;
 
     - unscheduled delays in the delivery of ordered materials and equipment;
 
     - unanticipated cost increases;
 
     - weather interferences;
 
     - difficulties in obtaining necessary permits or in meeting permit
       conditions;
 
     - design and engineering problems; and
 
     - shipyard failures.
 
  OUR BUSINESS INVOLVES NUMEROUS OPERATING HAZARDS.
 
     Our operations are subject to the usual hazards inherent in drilling for
oil and gas offshore, such as blowouts, reservoir damage, loss of production,
loss of well control, punchthroughs, craterings or fires. The occurrence of
these events could result in the suspension of drilling operations, damage to or
destruction of the equipment involved and injury or death to rig personnel.
Operations also may be suspended because of machinery breakdowns, abnormal
drilling conditions, failure of subcontractors to perform or supply goods or
services or personnel shortages. In addition, offshore drilling operators are
subject to perils peculiar to marine operations, including capsizing, grounding,
collision and loss or damage from severe weather. Damage to the environment
could also result from our operations, particularly through oil spillage or
extensive uncontrolled fires. We may also be subject to damage claims by oil and
gas companies.
 
     Although we maintain insurance in the areas in which we operate, pollution
and environmental risks generally are not fully insurable, and we do not
typically retain loss-of-life insurance policies to cover our rigs. Our
insurance policies and contractual rights to indemnity may not adequately cover
our losses, and we do not have insurance coverage or rights to indemnity for all
risks, including war risk. If a significant accident or other event occurs and
is not fully covered by insurance or contractual indemnity, it could adversely
affect our financial position and results of operations.
 
  OUR INTERNATIONAL OPERATIONS INVOLVE ADDITIONAL RISKS NOT ASSOCIATED WITH
  DOMESTIC OPERATIONS.
 
     We operate in various regions throughout the world that may expose us to
political and other uncertainties, including risks of:
 
     - war, terrorist activities and civil disturbances;
 
     - expropriation of property or equipment;
 
     - the inability to repatriate income or capital; and
 
     - changing taxation policies.
 
     International contract drilling operations are subject to various laws and
regulations in countries in which we operate, including laws and regulations
relating to:
 
     - the equipping and operation of drilling units;
 
     - repatriation of foreign earnings;
 
     - oil and gas exploration and development;
 
                                        9

 
     - taxation of offshore earnings and earnings of expatriate personnel; and
 
     - use and compensation of local employees and suppliers by foreign
       contractors.
 
     Governments in some foreign countries have become increasingly active in
regulating and controlling the ownership of concessions and companies holding
concessions, the exploration for oil and gas and other aspects of the oil and
gas industries in their countries. In addition, government action, including
initiatives by OPEC, may continue to cause oil price volatility. In some areas
of the world, this governmental activity has adversely affected the amount of
exploration and development work done by major oil companies and may continue to
do so. In addition, some foreign governments favor or effectively require the
awarding of drilling contracts to local contractors or require foreign
contractors to employ citizens of, or purchase supplies from, a particular
jurisdiction. These practices may adversely affect our ability to compete.
 
  FLUCTUATIONS IN EXCHANGE RATES AND NONCONVERTIBILITY OF CURRENCIES COULD
  RESULT IN LOSSES TO US.
 
     Due to our international operations, we may experience currency exchange
losses where revenues are received and expenses are paid in nonconvertible
currencies. We may also incur losses as a result of an inability to collect
revenues because of a shortage of convertible currency available to the country
of operation.
 
  FAILURE TO RETAIN HIGHLY SKILLED PERSONNEL COULD HURT OUR OPERATIONS.
 
     We require highly skilled personnel to operate and provide technical
services and support for our drilling units. To the extent demand for drilling
services and the size of the worldwide industry fleet increase, shortages of
qualified personnel could arise, creating upward pressure on wages, which could
adversely affect our results of operations.
 
  GOVERNMENTAL LAWS AND REGULATIONS MAY ADD TO OUR COSTS OR LIMIT OUR DRILLING
  ACTIVITY.
 
     Our operations are affected from time to time in varying degrees by
governmental laws and regulations. The drilling industry is dependent on demand
for services from the oil and gas exploration industry and, accordingly, is
affected by changing tax and other laws relating to the energy business
generally. We may be required to make significant capital expenditures to comply
with governmental laws and regulations. It is also possible that these laws and
regulations may in the future add significantly to our operating costs or may
significantly limit drilling activity.
 
  COMPLIANCE WITH OR BREACH OF ENVIRONMENTAL LAWS CAN BE COSTLY AND COULD LIMIT
  OUR OPERATIONS.
 
     In the United States, regulations controlling the discharge of materials
into the environment, requiring removal and cleanup of materials that may harm
the environment or otherwise relating to the protection of the environment apply
to some of our operations. For example, our company, as an operator of mobile
offshore drilling units in navigable United States waters and some offshore
areas, may be liable for damages and costs incurred in connection with oil
spills for which we are held responsible. Laws and regulations protecting the
environment have become more stringent in recent years, and may in some cases
impose "strict liability," rendering a person liable for environmental damage
without regard to negligence or fault on the part of that person. These laws and
regulations may expose us to liability for the conduct of or conditions caused
by others or for acts that were in compliance with all applicable laws at the
time they were performed. The application of these requirements or the adoption
of new requirements could have a material adverse effect on our financial
position and results of operations.
 
  WE ARE CONTROLLED BY A SINGLE STOCKHOLDER, WHICH COULD RESULT IN POTENTIAL
  CONFLICTS OF INTEREST.
 
     Loews Corporation, which we refer to as Loews, beneficially owns
approximately 54.5% of our outstanding shares of common stock and is in a
position to control actions that require the consent of stockholders, including
the election of directors, amendment of our Restated Certificate of
Incorporation and any merger or sale of substantially all of our assets. In
addition, three officers of Loews serve on our
 
                                        10

 
Board of Directors. One of those, James S. Tisch, the Chief Executive Officer
and Chairman of the Board of our company, is also the chief executive officer
and a director of Loews. We have also entered into a services agreement and a
registration rights agreement with Loews and we may in the future enter into
other agreements with Loews.
 
     Loews and its subsidiaries (other than us) and we are generally engaged in
businesses sufficiently different from each other as to make conflicts as to
possible corporate opportunities unlikely. However, it is possible that Loews
may in some circumstances be in direct or indirect competition with us,
including competition with respect to certain business strategies and
transactions that we may propose to undertake. In addition, potential conflicts
of interest exist or could arise in the future for such directors with respect
to a number of areas relating to the past and ongoing relationships of Loews and
us, including tax and insurance matters, financial commitments and sales of
common stock pursuant to registration rights or otherwise. Although the affected
directors may abstain from voting on matters in which our interests and those of
Loews are in conflict so as to avoid potential violations of their fiduciary
duties to stockholders, the presence of potential or actual conflicts could
affect the process or outcome of Board deliberations. Our directors are subject
to our Code of Business Conduct and Ethics, but we have not adopted any other
policies, procedures or practices to reduce or avoid these conflicts. We cannot
assure you that these conflicts of interest will not materially adversely affect
us.
 
RISKS RELATING TO THE REGISTERED NOTES AND THE EXCHANGE OFFER
 
  OUR HOLDING COMPANY STRUCTURE RESULTS IN SUBSTANTIAL STRUCTURAL SUBORDINATION
  AND MAY AFFECT OUR ABILITY TO MAKE PAYMENTS ON THE NOTES.
 
     The notes are obligations exclusively of Diamond Offshore Drilling, Inc. We
are a holding company and substantially all operations are conducted by our
subsidiaries. As a result, our cash flow and our ability to service our debt,
including the notes, is dependent upon the earnings of our subsidiaries. In
addition, we are dependent on the distribution of earnings, loans or other
payments by our subsidiaries to us.
 
     Our subsidiaries are separate and distinct legal entities. Our subsidiaries
have no obligation to pay any amounts due on the notes or to provide us with
funds for our payment obligations, whether by dividends, distributions, loans or
other payments. In addition, any payment of dividends, distributions, loans or
advances by our subsidiaries to us could be subject to statutory or contractual
restrictions. Payments to us by our subsidiaries will also be contingent upon
their earnings and business considerations.
 
     Our right to receive any assets of any of our subsidiaries upon their
liquidation or reorganization, and therefore the right of the holders of the
notes to participate in the profits or a distribution of those assets, will be
effectively subordinated to the claims of that subsidiary's creditors, including
trade creditors. In addition, even if we were a creditor of any of our
subsidiaries, our rights as a creditor would be subordinate to any security
interest in the assets of our subsidiaries and any indebtedness of our
subsidiaries senior to that held by us.
 
  OUR DEBT AGREEMENTS ALLOW US TO INCUR SIGNIFICANTLY MORE DEBT, WHICH, IF
  INCURRED, COULD EXACERBATE THE OTHER RISKS DESCRIBED IN THIS PROSPECTUS.
 
     The terms of our debt instruments permit us to incur additional
indebtedness. Such debt may be necessary to comply with regulatory obligations
to maintain our assets, to satisfy regulatory service obligations, to adequately
respond to competition or for financial reasons alone. Incremental borrowings or
borrowings at maturities that impose additional financial risks to our various
efforts to improve our financial condition and results of operations would
exacerbate the other risks described in this prospectus.
 
                                        11

 
  OTHER THAN COVENANTS LIMITING LIENS, CERTAIN SALE AND LEASEBACK TRANSACTIONS
  AND CERTAIN CORPORATE TRANSACTIONS, THE INDENTURE GOVERNING THE NOTES DOES NOT
  CONTAIN RESTRICTIVE COVENANTS.
 
     The indenture governing the notes does not contain restrictive covenants
that would protect you from many kinds of transactions that may adversely affect
you. In particular, the indenture does not contain covenants limiting any of the
following:
 
     - the incurrence of additional indebtedness by us or our subsidiaries;
 
     - the issuance of stock of our subsidiaries;
 
     - the payment of dividends and certain other payments by us and our
       subsidiaries;
 
     - our creation of restrictions on the ability of our subsidiaries to make
       payments to us;
 
     - our ability to enter into certain transactions with affiliates; or
 
     - our ability to enter into a transaction constituting a change of control.
 
  IF YOU FAIL TO EXCHANGE YOUR OLD NOTES, THEY WILL CONTINUE TO BE RESTRICTED
  SECURITIES AND MAY BECOME LESS LIQUID.
 
     Following the exchange offer, old notes that you do not tender or we do not
accept will continue to be restricted securities. You may not offer or sell
untendered old notes except pursuant to an exemption from, or in a transaction
not subject to, the Securities Act and applicable state securities laws. We will
issue registered notes in exchange for the old notes pursuant to the exchange
offer only following the satisfaction of the procedures and conditions described
elsewhere in this prospectus. These procedures and conditions include timely
receipt by the exchange agent of the old notes and of a properly completed and
duly executed letter of transmittal. Because we anticipate that most holders of
old notes will elect to exchange their old notes, we expect that the liquidity
of the market for any old notes remaining after the completion of the exchange
offer may be substantially limited and this may have an adverse effect upon, and
increase the volatility of, the market price of any old notes that you continue
to hold following completion of the exchange offer.
 
  THERE MAY BE NO ACTIVE TRADING MARKET FOR THE REGISTERED NOTES.
 
     The registered notes are a new issue of securities for which there is
currently no active trading market. We do not intend to apply for listing the
registered notes on any securities exchange or automated quotation system. If
the registered notes are traded after they are initially issued, they may trade
at a discount from their initial offering price. The trading price of the
registered notes will depend on the market for similar securities and other
factors, including economic conditions and our financial condition, performance
and prospects. If an active market does not develop or is not maintained, the
trading price and liquidity of the registered notes may be adversely affected.
 
               SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS
 
     This prospectus and the documents incorporated by reference in this
prospectus contain both historical and forward-looking statements. All
statements other than statements of historical fact are, or may be deemed to be,
forward-looking statements within the meaning of Section 27A of the Securities
Act and Section 21E of the Exchange Act. Forward-looking statements include the
information concerning possible or assumed future results of operations of our
company, including statements about the following subjects:
 
     - future market conditions and the effect of such conditions on our future
       results of operations
 
     - interest rate and foreign exchange risk
 
     - business strategy
 
     - growth opportunities
 
                                        12

 
     - competitive position
 
     - market outlook
 
     - expected financial position
 
     - expected results of operations
 
     - future cash flows
 
     - future operations outside the United States
 
     - future contractual obligations
 
     - future dividends
 
     - financing plans
 
     - tax planning
 
     - budgets for capital and other expenditures
 
     - timing and cost of completion of rig upgrades and other capital projects
 
     - plans and objectives of management
 
     - performance of contracts
 
     - outcomes of legal proceedings
 
     - compliance with applicable laws
 
     - adequacy of insurance
 
     - future uses of and requirements for financial resources
 
     - expenditures, delivery dates and drilling contracts related to conversion
       or upgrade projects
 
     Forward-looking statements in this prospectus or incorporated by reference
are identifiable by use of the following words and other similar expressions,
among others:
 

                                         
- "anticipate"                              - "may"
- "believe"                                 - "might"
- "budget"                                  - "plan"
- "could"                                   - "predict"
- "estimate"                                - "project"
- "expect"                                  - "should"
- "forecast"                                - "will"
- "intend"

 
     The factors discussed above under "Risk Factors" and in the documents we
incorporate by reference into this prospectus could affect our future results of
operations and could cause actual results to differ materially from those
expressed in the forward-looking statements included in this prospectus or
incorporated by reference. These factors include, among others:
 
     - general economic and business conditions
 
     - worldwide demand for oil and gas
 
     - oil and natural gas price fluctuations and related market expectations
 
     - market conditions in the offshore contract drilling industry, including
       dayrates and utilization levels
 
                                        13

 
     - the ability of OPEC to set and maintain production levels and pricing,
       and the level of production in non-OPEC countries
 
     - policies of the various governments regarding exploration and development
       of oil and natural gas reserves
 
     - casualty losses
 
     - industry fleet capacity
 
     - changes in foreign and domestic oil and gas exploration, development and
       production activity
 
     - competition
 
     - changes in foreign, political, social and economic conditions
 
     - risks of international operations, compliance with foreign laws and
       taxation policies and expropriation or nationalization of equipment and
       assets
 
     - foreign exchange and currency fluctuations and regulations, and the
       inability to repatriate income or capital
 
     - risks of war, military operations, other armed hostilities, terrorist
       acts and embargoes
 
     - regulatory initiatives and compliance with governmental regulations
 
     - compliance with environmental laws and regulations
 
     - advances in exploration and development technology
 
     - changes in offshore drilling technology, which could require significant
       capital expenditures in order to maintain competitiveness
 
     - the political environment of oil-producing regions
 
     - operating hazards inherent in drilling for oil and gas offshore
 
     - effects of litigation
 
     - cost, availability and adequacy of insurance
 
     - adequacy of our sources of liquidity
 
     - availability of qualified personnel to operate and service our drilling
       rigs
 
     - risks of potential contractual liabilities pursuant to our various
       drilling contracts in effect from time to time
 
     - risks inherent in turnkey operations, including the risk of failure to
       complete a well and cost overruns
 
     - customer preferences and
 
     - various other matters, many of which are beyond our control.
 
     You should not place undue reliance on forward-looking statements. Each
forward-looking statement speaks only as of the date of the particular
statement, and we undertake no obligation to publicly update or revise any
forward-looking statements.
 
                                USE OF PROCEEDS
 
     The exchange offer is intended to satisfy our obligations under the
registration rights agreement. We will not receive any cash proceeds from the
issuance of the registered notes. In consideration for issuing the registered
notes as contemplated in this prospectus, we will receive, in exchange, an equal
number of outstanding old notes in like principal amount. The form and terms of
the registered notes are substantially
                                        14

 
identical in all material respects to the form and terms of the old notes,
except for transfer restrictions, registration rights and additional interest
payment provisions relating only to the old notes. The outstanding old notes
surrendered in exchange for the registered notes will be retired and marked as
cancelled and cannot be reissued.
 
                       RATIO OF EARNINGS TO FIXED CHARGES
 
     Our ratio of earnings to fixed charges for each of the periods shown is as
follows:
 


                                   NINE MONTHS ENDED
                                     SEPTEMBER 30,           YEAR ENDED DECEMBER 31,
                                   ------------------   ---------------------------------
                                    2004        2003    2003   2002   2001   2000   1999
                                   ------      ------   ----   ----   ----   ----   -----
                                                               
Ratio of earnings to fixed
  charges........................    N/A         N/A    N/A    4.51   9.87   4.97   15.64

 
     The deficiency in our earnings available for fixed charges for the nine
months ended September 30, 2004 and 2003 was approximately $23.5 million and
$60.5 million, respectively. The deficiency in our earnings available for fixed
charges for the year ended December 31, 2003 was approximately $55.3 million.
For all periods presented, the ratio of earnings to fixed charges has been
computed on a total enterprise basis. Earnings represent income from continuing
operations plus income taxes and fixed charges. Fixed charges include (1)
interest, whether expensed or capitalized, (2) amortization of debt issuance
costs, whether expensed or capitalized, and (3) one-third of rent expense, which
we believe represents the interest factor attributable to rent.
 
                                        15

 
                      SELECTED CONSOLIDATED FINANCIAL DATA
 
     The following table sets forth certain historical consolidated financial
data relating to our company. The selected consolidated financial data are
derived from our financial statements as of and for the periods presented. You
should read the selected consolidated financial data below in conjunction with
"Management's Discussion and Analysis of Financial Condition and Results of
Operations" and our consolidated financial statements and the related notes
included in our Annual Report on Form 10-K and on our Quarterly Reports on Form
10-Q incorporated by reference in this prospectus.
 


                           NINE MONTHS ENDED
                             SEPTEMBER 30,                  AS OF AND FOR THE YEAR ENDED DECEMBER 31,
                        -----------------------   --------------------------------------------------------------
                           2004         2003         2003         2002         2001         2000         1999
                        ----------   ----------   ----------   ----------   ----------   ----------   ----------
                                                              (IN THOUSANDS, EXCEPT PER SHARE DATA)
                                                                                 
INCOME STATEMENT DATA:
Total revenues........  $  577,342   $  493,256   $  680,941   $  752,561   $  924,300   $  684,501   $  858,868
Operating (loss)
  income..............     (11,534)     (47,557)     (38,323)      51,984      225,410       71,499      224,285
Net (loss) income.....     (18,526)     (49,716)     (48,414)      62,520      173,823       72,281      156,071
Net (loss) income per
  share:
  Basic...............       (0.14)       (0.38)       (0.37)        0.48         1.31         0.53         1.15
  Diluted.............       (0.14)       (0.38)       (0.37)        0.47         1.26         0.53         1.11
BALANCE SHEET DATA:
Drilling and other
  property and
  equipment, net......  $2,190,616   $2,270,377   $2,257,876   $2,164,627   $2,002,873   $1,931,182   $1,737,905
Total assets..........   3,341,576    3,137,293    3,135,019    3,256,308    3,493,071    3,073,191    2,674,865
Long-term debt
  (excluding current
  maturities).........     722,220      936,075      928,030      924,475      920,636      856,559      400,000
OTHER FINANCIAL DATA:
Capital
  expenditures(1).....  $   69,719   $  240,916   $  272,026   $  340,805   $  268,617   $  323,924   $  324,133
Cash dividends
  declared per
  share...............      0.1875        0.375        0.438         0.50         0.50         0.50         0.50

 
---------------
 
(1) In March 2003 we spent $65.0 million ($63.5 million capitalized to rig
    equipment and $1.5 million added to inventory) for the acquisition of the
    Ocean Patriot, a third-generation semisubmersible drilling rig. In December
    2002 we spent $68.5 million ($67.0 million capitalized to rig equipment and
    $1.5 million added to inventory) for the acquisition of another
    third-generation semisubmersible drilling rig, the Ocean Vanguard.
 
                               THE EXCHANGE OFFER
 
PURPOSE AND EFFECT
 
     We issued the old notes on August 27, 2004, in a private placement to a
limited number of qualified institutional buyers as defined under the Securities
Act, persons outside the United States and institutional accredited investors as
defined under the Securities Act. In connection with this original issuance, we
entered into an indenture and a registration rights agreement. The registration
rights agreement requires that we file a registration statement under the
Securities Act with respect to the registered notes to be issued in the exchange
offer and, upon the effectiveness of the registration statement, offer you the
opportunity to exchange your old notes for a like principal amount of registered
notes. We agreed in the registration rights agreement to use our best efforts to
commence and complete the exchange offer promptly, but no later than 45 days
after the registration statement has become effective, and to hold the exchange
offer open for at least 30 days. Except as set forth below, these registered
notes will be issued without a restrictive legend and, we believe, may be
reoffered and resold by you without registration under the Securities Act. After
we complete the exchange offer, our obligations with respect to the registration
of the old notes and the registered notes will terminate, except as provided
below under "-- Registration
 
                                        16

 
Rights." Copies of the indenture relating to the notes and the registration
rights agreement have been filed as exhibits to our current report on Form 8-K
filed on September 1, 2004. Notwithstanding anything to the contrary set forth
in this prospectus, this exchange offer is not being made to you, and you may
not participate in the exchange offer, if (a) you are our "affiliate" within the
meaning of Rule 405 under the Securities Act or (b) you are a broker-dealer that
acquired old notes directly from us.
 
     Based on an interpretation by the staff of the SEC set forth in no-action
letters issued to third parties unrelated to us, we believe that the registered
notes issued to you in the exchange offer may be offered for resale, resold and
otherwise transferred by you, without compliance with the registration and
prospectus delivery provisions of the Securities Act, unless you are a
broker-dealer that receives registered notes in exchange for old notes acquired
by you as a result of market-making or other trading activities. This
interpretation, however, is based on your representations to us that:
 
          (1) the registered notes to be issued to you in the exchange offer are
     being acquired in the ordinary course of your business;
 
          (2) you are not engaging in and do not intend to engage in a
     distribution of the registered notes to be issued to you in the exchange
     offer; and
 
          (3) you have no arrangement or understanding with any person to
     participate in the distribution of the registered notes to be issued to you
     in the exchange offer.
 
     If you have any of the disqualifications described above or cannot make
each of the representations set forth above, you may not rely on the
interpretation by the staff of the SEC referred to above. Under those
circumstances, you must comply with the registration and prospectus delivery
requirements of the Securities Act in connection with a sale, transfer or other
disposition of any notes unless you are able to utilize an applicable exemption
from all of those requirements. In addition, each broker-dealer that receives
registered notes for its own account in exchange for old notes acquired by such
broker-dealer as a result of market-making activities or other trading
activities must acknowledge that it will deliver a prospectus in connection with
any resale of those registered notes. See "Plan of Distribution."
 
  REGISTRATION RIGHTS
 
     If:
 
          (1) on or before the completion of the exchange offer, the existing
     SEC interpretations are changed such that the registered notes would not in
     general be freely transferable under the Securities Act on such date;
 
          (2) the exchange offer has not been completed by April 9, 2005; or
 
          (3) a holder of notes notifies us in writing prior to the 20th day
     following consummation of the exchange offer that the exchange offer is not
     available to such holder,
 
we have agreed to file, in lieu of (or, in the case of clause (3), in addition
to) conducting the exchange offer, as soon as reasonably practicable (but no
later than 60 days after the time such obligation to file arises), a
registration statement, which we refer to as the shelf registration statement,
under the Securities Act. If filed, the shelf registration statement will relate
to a "shelf" registration pursuant to Rule 415 under the Securities Act, which
we refer to as the resale registration, of the notes for resale by holders of
such notes who satisfy certain conditions relating to the provision of
information in connection with the shelf registration statement. We will use our
reasonable efforts to cause the shelf registration statement to become effective
within 120 days following the date, if any, that such shelf registration
statement is filed and to keep such shelf registration statement continuously
effective until the earlier of two years following the effective date of such
shelf registration statement or such shorter period that will terminate when all
the securities covered by the shelf registration statement have been sold
pursuant to the shelf registration statement or are distributed to the public
pursuant to Rule 144 or become eligible for resale pursuant to Rule 144 without
volume restriction.
 
                                        17

 
     We will, in the event of the resale registration, provide to the holder or
holders of the applicable notes copies of the prospectus that is a part of the
shelf registration statement, notify such holder or holders when the resale
registration for the applicable notes has become effective and take certain
other actions as are required to permit unrestricted resales of the applicable
notes. A holder of notes that sells such notes pursuant to the resale
registration generally would be required to be named as a selling securityholder
in the related prospectus and to deliver a prospectus to purchasers, will be
subject to certain of the civil liability provisions under the Securities Act in
connection with such sales and will be bound by the provisions of the
registration rights agreement that are applicable to such a holder (including
certain indemnification obligations). Although we intend to file the
registration statement previously described, if it is required, we cannot assure
you that the registration statement will be filed or, if filed, that it will
become effective.
 
     The registration rights agreement provides, among other things, that if we
default in our obligations to take required actions to make the exchange offer
within certain required time periods, or if any exchange offer registration
statement or shelf registration statement required by the registration rights
agreement is filed and declared effective but shall thereafter cease to be
effective during the periods specified in the registration rights agreement
(except as specifically permitted therein) without being succeeded promptly by
an additional registration statement filed and declared effective, any of which
events we refer to as a registration default, then we will pay to the holders of
notes, as liquidated damages, for the period from the occurrence of the
registration default until such time as no registration default is in effect, an
amount per annum equal to 0.25% of the aggregate principal amount of such notes
during the first 90-day period following the occurrence of such registration
default and a per annum rate of 0.50% thereafter for any remaining period in
which a registration default continues. In no event will the interest rate in
respect of a registration default exceed 0.50% per year. Liquidated damages
shall be paid on interest payment dates to the holders of record for the payment
of interest.
 
     The summary herein of certain provisions of the registration rights
agreement does not purport to be complete and is subject to, and is qualified in
its entirety by reference to, all the provisions of the registration rights
agreement. We urge you to read the registration rights agreement in its entirety
because it, and not this description, defines your rights as holders of the
notes. You can receive a copy of the registration rights agreement upon request
to us at the address or telephone number set forth above under "Where You Can
Find More Information."
 
CONSEQUENCES OF FAILURE TO EXCHANGE
 
     After we complete the exchange offer, if you have not tendered your old
notes, or if you have tendered and subsequently withdrawn your old notes, you
will not have any further registration rights, except in the limited
circumstances set forth above. Your old notes will continue to be subject to
restrictions on transfer. In general, you may not offer or sell the old notes
unless either they are registered under the Securities Act or the offer or sale
is exempt from or not subject to the registration requirements under the
Securities Act and applicable state securities laws. Except as required by the
registration rights agreement, we do not intend to register resales of the old
notes under the Securities Act. In addition, the tender of old notes in the
exchange offer will reduce the principal amount of the old notes outstanding.
Therefore, the liquidity of the market for your old notes could be adversely
affected upon completion of the exchange offer and this may have an adverse
effect upon, and increase the volatility of, the market price of any old notes
that you continue to hold following completion of the exchange offer.
 
TERMS OF THE EXCHANGE OFFER
 
     Upon the terms and subject to the conditions set forth in this prospectus
and in the letter of transmittal for your notes, we will accept any and all old
notes validly tendered and not withdrawn prior to the time of expiration. We
will issue a principal amount of registered notes in exchange for the principal
amount of old notes accepted in the exchange offer. You may tender some or all
of your old notes pursuant to the exchange offer. However, old notes may be
tendered only in integral multiples of $1,000 principal amount.
                                        18

 
     The form and terms of the registered notes are substantially identical in
all material respects as the form and terms of the old notes, except that the
registered notes to be issued in the exchange offer have been registered under
the Securities Act and will not bear legends restricting their transfer and the
registered notes will not be entitled to the additional interest payment
provisions relating only to the old notes. The registered notes will be issued
pursuant to, and entitled to the benefits of, the indenture which governs the
old notes. The registered notes and old notes will be deemed a single series of
securities for all purposes under the indenture, including, without limitation,
waivers, amendments, redemptions and offers to purchase.
 
     As of the date of this prospectus, $250.0 million aggregate principal
amount of old notes were outstanding. This prospectus, together with the letter
of transmittal, is being sent to all registered holders and to others believed
to have beneficial interests in the old notes. We intend to conduct the exchange
offer in accordance with the applicable requirements of the Exchange Act and the
rules and regulations of the SEC promulgated under the Exchange Act.
 
     We will be deemed to have accepted validly tendered outstanding notes when,
as, and if we have given oral or written notice of our acceptance to the
exchange agent. The exchange agent will act as our agent for the tendering
holders for the purpose of receiving the registered notes from us. If we do not
accept any tendered notes because of an invalid tender or the failure of any of
the conditions to the exchange offer to be satisfied, we will return the
unaccepted old notes, without expense, to the tendering holder promptly after
the time of expiration. The conditions to the exchange offer are listed below
under the heading "-- Conditions."
 
     You will not be required to pay brokerage commissions or fees or, except as
set forth below under "-- Transfer Taxes," transfer taxes with respect to the
exchange of your old notes in the exchange offer. We will pay all charges and
expenses, other than applicable taxes, in connection with the exchange offer.
See "-- Fees and Expenses" below.
 
     In connection with the exchange offer, neither the General Corporation Law
of the State of Delaware nor the indenture governing the notes gives you any
appraisal or dissenters' rights. We intend to conduct the exchange offer in
accordance with the provisions of the registration rights agreement and the
applicable requirements of the Exchange Act and the related SEC rules and
regulations.
 
EXPIRATION; AMENDMENTS
 
     The exchange offer will expire at 5:00 P.M., New York City time, on March
14, 2005, unless we determine, in our sole discretion, to extend the exchange
offer, in which case it will expire at the later date and time to which it is
extended. We do not intend to extend the exchange offer, although we reserve the
right to do so. If we do extend the exchange offer, we will give oral or written
notice of the extension to the exchange agent and give each registered holder of
outstanding notes for which the exchange offer is being made notice by means of
a press release or other public announcement of any extension prior to 9:00
a.m., New York City time, on the next business day after the scheduled
expiration for the exchange offer.
 
     We also reserve the right, in our sole discretion,
 
          (1) to delay accepting any old notes or, if any of the conditions set
     forth below under "-- Conditions" have not been satisfied or waived, to
     terminate the exchange offer by giving oral or written notice of the delay
     or termination to the exchange agent; or
 
          (2) to amend the terms of the exchange offer in any manner, by
     complying with Rule 14e-1(d) under the Exchange Act to the extent that rule
     applies.
 
     Except as specified in the first paragraph under this heading, we will make
a public announcement of any such delay in acceptance, extension, termination or
amendment as promptly as practicable. If we amend the exchange offer in a manner
determined by us to constitute a material change, we will promptly disclose such
amendment in a prospectus supplement that will be distributed to the registered
holders of
 
                                        19

 
the notes. The exchange offer will then be extended for a period of five to 10
business days, as required by law, depending upon the significance of the
amendment and the manner of disclosure to the registered holders, if the
exchange offer would otherwise expire during the five to 10 business days
period.
 
     We will make a timely release of a public announcement of any delay,
extension, termination or amendment to the exchange offer to an appropriate news
agency.
 
PROCEDURES FOR TENDERING
 
  BOOK ENTRY INTERESTS
 
     The old notes were issued as global notes in fully registered form without
interest coupons. Beneficial interests in the global notes, held by direct or
indirect participants in DTC, are shown on, and transfers of these interests are
effected only through, records maintained in book-entry form by DTC with respect
to its participants.
 
     If you hold old notes in the form of book-entry interests and you wish to
tender your old notes for exchange pursuant to the exchange offer, you must
transmit to the exchange agent prior to the time of expiration either:
 
          (1) a written or facsimile copy of a properly completed and duly
     executed letter of transmittal for your notes, including all other
     documents required by the letter of transmittal, to the exchange agent at
     the address set forth on the cover page of the letter of transmittal; or
 
          (2) a computer-generated message transmitted by means of DTC's
     Automated Tender Offer Program system and received by the exchange agent
     and forming a part of a confirmation of book-entry transfer, in which you
     acknowledge and agree to be bound by the terms of the letter of transmittal
     for your notes.
 
     In addition, in order to deliver old notes held in the form of book-entry
interests:
 
          (1) a timely confirmation of book-entry transfer of those notes into
     the exchange agent's account at DTC pursuant to the procedure for
     book-entry transfers described below under "-- Book-Entry Transfer" must be
     received by the exchange agent prior to the time of expiration; or
 
          (2) you must comply with the guaranteed delivery procedures described
     below.
 
     The method of delivery of old notes and the letter of transmittal and all
other required documents to the exchange agent is at your election and risk.
Instead of delivery by mail, we recommend that you use an overnight or hand
delivery service. In all cases, sufficient time should be allowed to assure
delivery to the exchange agent before the time of expiration. You should not
send the letter of transmittal or old notes to us. You may request your broker,
dealer, commercial bank, trust company or other nominee to effect the above
transactions for you.
 
  CERTIFICATED OLD NOTES
 
     Only registered holders of certificated old notes may tender those notes in
the exchange offer. If your old notes are certificated notes and you wish to
tender those notes for exchange pursuant to the exchange offer, you must
transmit to the exchange agent prior to the time of expiration, a written or
facsimile copy of a properly completed and duly executed letter of transmittal,
including all other required documents, to the address set forth below under
"-- Exchange Agent." In addition, in order to validly tender your certificated
old notes:
 
          (1) the certificates representing your old notes must be received by
     the exchange agent prior to the time of expiration; or
 
          (2) you must comply with the guaranteed delivery procedures described
     below.
 
                                        20

 
  PROCEDURES APPLICABLE TO ALL HOLDERS
 
     If you tender an old note and you do not withdraw the tender prior to the
time of expiration, you will have made an agreement with us in accordance with
the terms and subject to the conditions set forth in this prospectus and in the
letter of transmittal for your notes.
 
     If your old notes are registered in the name of a broker, dealer,
commercial bank, trust company or other nominee and you wish to tender your
notes, you should contact the registered holder promptly and instruct the
registered holder to tender on your behalf. If you wish to tender on your own
behalf, you must, prior to completing and executing the letter of transmittal
for your notes and delivering your old notes, either make appropriate
arrangements to register ownership of the old notes in your name or obtain a
properly completed bond power from the registered holder. The transfer of
registered ownership may take considerable time.
 
     Signatures on a letter of transmittal or a notice of withdrawal must be
guaranteed by a financial institution, including most banks, savings and loan
associations and brokerage houses, that is a participant in the Securities
Transfer Agents Medallion Program, the New York Stock Exchange Medallion Program
or the Stock Exchange Medallion Program, each an "eligible institution," unless:
 
          (1) old notes tendered in the exchange offer are tendered either:
 
             (A) by a registered holder who has not completed the box entitled
        "Special Issuance Instructions" or "Special Delivery Instructions" on
        the holder's applicable letter of transmittal; or
 
             (B) for the account of an eligible institution; and
 
          (2) the box entitled "Special Registration Instructions" on the letter
     of transmittal has not been completed.
 
     If the letter of transmittal for your notes is signed by a person other
than you, your old notes must be endorsed or accompanied by a properly completed
bond power and signed by you as your name appears on those old notes.
 
     If the letter of transmittal for your notes or any old notes or bond powers
are signed by trustees, executors, administrators, guardians, attorneys-in-fact,
officers of corporations or others acting in a fiduciary or representative
capacity, those persons should so indicate when signing. Unless we waive this
requirement, in this instance you must submit with the letter of transmittal for
your notes proper evidence satisfactory to us of their authority to act on your
behalf.
 
     We will determine, in our sole discretion, all questions regarding the
validity, form, eligibility, including time of receipt, acceptance and
withdrawal of tendered old notes. This determination will be final and binding.
We reserve the absolute right to reject any and all old notes not properly
tendered or any old notes our acceptance of which would, in the opinion of our
counsel, be unlawful. We also reserve the right to waive any defects,
irregularities or conditions of tender as to particular old notes. Our
interpretation of the terms and conditions of the exchange offer, including the
instructions in the letter of transmittal for your notes, will be final and
binding on all parties.
 
     You must cure any defects or irregularities in connection with tenders of
your old notes within the time period we determine unless we waive that defect
or irregularity. Although we intend to notify you of defects or irregularities
with respect to your tender of old notes, neither we, the exchange agent nor any
other person will incur any liability for failure to give this notification.
Your tender will not be deemed to have been made and your notes will be returned
to you if:
 
          (1) you improperly tender your old notes;
 
          (2) you have not cured any defects or irregularities in your tender;
     and
 
          (3) we have not waived those defects, irregularities or improper
     tender.
 
                                        21

 
The exchange agent will return your notes, unless otherwise provided in the
letter of transmittal for your notes, as soon as practicable following the
expiration of the exchange offer.
 
     We reserve the right in our sole discretion to:
 
          (1) purchase or make offers for, or offer registered notes for, any
     old notes that remain outstanding subsequent to the expiration of the
     exchange offer;
 
          (2) terminate the exchange offer upon the failure of any condition to
     the exchange offer to be satisfied; and
 
          (3) to the extent permitted by applicable law, purchase notes in the
     open market, in privately negotiated transactions or otherwise.
 
     The terms of any of these purchases or offers could differ from the terms
of the exchange offer.
 
     By tendering in the exchange offer, you will represent to us that, among
other things:
 
          (1) the registered notes to be issued to you in the exchange offer are
     being acquired in the ordinary course of your business;
 
          (2) you are not engaging in and do not intend to engage in a
     distribution of the registered notes to be issued to you in the exchange
     offer;
 
          (3) you do not have an arrangement or understanding with any person to
     participate in the distribution of the registered notes to be acquired by
     you in the exchange offer; and
 
          (4) you are not our "affiliate," as defined in Rule 405 under the
     Securities Act.
 
     In all cases, issuance of registered notes for old notes that are accepted
for exchange in the exchange offer will be made only after timely receipt by the
exchange agent of certificates for your old notes or a timely confirmation of
book-entry transfer of your old notes into the exchange agent's account at DTC,
a properly completed and duly executed letter of transmittal for your notes and
all other required documents. If any tendered old notes are not accepted for any
reason set forth in the terms and conditions of the exchange offer or if old
notes are submitted for a greater principal amount than you desire to exchange,
the unaccepted or non-exchanged old notes, or old notes in substitution
therefor, will be returned without expense to you. In addition, in the case of
old notes tendered by book-entry transfer into the exchange agent's account at
DTC pursuant to the book-entry transfer procedures described below, the non-
exchanged old notes will be credited to your account maintained with DTC, as
promptly as practicable after the expiration or termination of the exchange
offer.
 
  GUARANTEED DELIVERY PROCEDURES
 
     If you desire to tender your old notes and your old notes are not
immediately available or one of the situations specified above occurs, you may
tender if:
 
          (1) you tender through an eligible institution;
 
          (2) prior to the time of expiration, the exchange agent receives from
     an eligible institution a written or facsimile copy of a properly completed
     and duly executed letter of transmittal for your notes and notice of
     guaranteed delivery for your notes, substantially in the form provided by
     us; and
 
          (3) the certificates for all certificated old notes, in proper form
     for transfer, or a book-entry confirmation, and all other documents
     required by the letter of transmittal for your notes, are received by the
     exchange agent within three New York Stock Exchange trading days after the
     date of execution of the notice of guaranteed delivery for your notes.
 
                                        22

 
     The notice of guaranteed delivery for your notes may be sent by facsimile
transmission, mail or hand delivery. The notice of guaranteed delivery must set
forth:
 
          (1) your name and address;
 
          (2) the amount of old notes you are tendering; and
 
          (3) a statement that your tender is being made by the notice of
     guaranteed delivery for your notes and that you guarantee that within three
     New York Stock Exchange trading days after the execution of the notice of
     guaranteed delivery, the eligible institution will deliver the following
     documents to the exchange agent:
 
             (A) the certificates for all certificated old notes being tendered,
        in proper form for transfer, or a book-entry confirmation of tender;
 
             (B) a written or facsimile copy of the letter of transmittal for
        your notes, or a book-entry confirmation instead of the letter of
        transmittal; and
 
             (C) any other documents required by the letter of transmittal for
        your notes.
 
BOOK-ENTRY TRANSFER
 
     The exchange agent will establish accounts with respect to book-entry
interests at DTC for purposes of the exchange offer promptly after the date of
this prospectus. You must deliver a book-entry interest by book-entry transfer
to the account maintained by the exchange agent at DTC for the exchange offer.
Any financial institution that is a participant in DTC's systems may make
book-entry delivery of book-entry interests by causing DTC to transfer the
book-entry interests into the relevant account of the exchange agent at DTC in
accordance with DTC's procedures for transfer.
 
     If one of the following situations occurs:
 
          (1) you cannot deliver a book-entry confirmation of book-entry
     delivery of your book-entry interests into the relevant account of the
     exchange agent at DTC; or
 
          (2) you cannot deliver all other documents required by the letter of
     transmittal to the exchange agent prior to the time of expiration,
 
then you must tender your book-entry interests according to the guaranteed
delivery procedures discussed above.
 
WITHDRAWAL RIGHTS
 
     You may withdraw tenders of your old notes at any time prior to the time of
expiration.
 
     For your withdrawal to be effective, the exchange agent must receive a
written or facsimile transmission notice of withdrawal at its address set forth
below under "-- Exchange Agent" prior to the time of expiration.
 
     The notice of withdrawal must:
 
          (1) state your name;
 
          (2) identify the specific old notes to be withdrawn, including the
     certificate number or numbers and the principal amount of old notes to be
     withdrawn;
 
          (3) be signed by you in the same manner as you signed the letter of
     transmittal for your notes when you tendered your old notes, including any
     required signature guarantees, or be accompanied by documents of transfer
     sufficient for the exchange agent to register the transfer of the old notes
     into your name; and
 
          (4) specify the name in which the old notes are to be registered, if
     different from yours.
 
                                        23

 
     We will determine all questions regarding the validity, form and
eligibility, including time of receipt, of withdrawal notices. Our determination
will be final and binding on all parties. Any old notes withdrawn will be deemed
not to have been validly tendered for exchange for purposes of the exchange
offer. Any old notes which have been tendered for exchange but which are not
exchanged for any reason will be returned to you without cost promptly after
withdrawal, rejection of tender or termination of the exchange offer. Properly
withdrawn old notes may be retendered by following one of the procedures
described under "-- Procedures for Tendering" above at any time prior to the
time of expiration.
 
CONDITIONS
 
     Despite any other provision of the exchange offer and subject to our
obligations under the registration rights agreement, we will not be required to
accept for exchange, or to issue registered notes in exchange for, any old notes
in the exchange offer and may terminate or amend the exchange offer if, at any
time before completion of the exchange offer, in our reasonable judgment the
exchange offer, or the making of any exchange by a holder of old notes, would
violate any applicable law, regulation or interpretation of the staff of the SEC
or would be prohibited or impaired by any action or proceeding that has been
instituted or threatened in any court or by or before any governmental agency
with respect to the exchange offer. In addition, we will not be obligated to
accept for exchange the old notes of any holder that has not made to us the
representations described above under "-- Procedures for Tendering -- Procedures
Applicable to All Holders" and in the letter of transmittal.
 
     These conditions are for our sole benefit and we may assert them regardless
of the circumstances giving rise to them, subject to the terms of the
registration rights agreement and applicable law. We also may waive in whole or
in part at any time and from time to time any particular condition to the
exchange offer in our sole discretion. If we waive a condition, we may be
required in order to comply with applicable securities laws to extend the
expiration of the exchange offer. Our failure at any time to exercise any of the
foregoing rights will not be deemed a waiver of these rights, and these rights
will be deemed ongoing rights which may be asserted at any time or at various
times.
 
     In addition, we will not accept for exchange any old notes tendered, and no
registered notes will be issued in exchange for any of those old notes, if at
the time the notes are tendered any stop order is threatened by the SEC or in
effect with respect to the registration statement of which this prospectus is a
part or the qualification of the indenture under the Trust Indenture Act of
1939, as amended.
 
     The exchange offer is not conditioned upon any minimum principal amount of
old notes being tendered for exchange.
 
EXCHANGE AGENT
 
     We have appointed JPMorgan Chase Bank, N.A. as exchange agent for the
exchange offer. Questions, requests for assistance and requests for additional
copies of the prospectus, the letter of transmittal for your notes and other
related documents should be directed to the exchange agent addressed as follows:
 
                        By Certified or Registered Mail:
                           JPMorgan Chase Bank, N.A.
                          Institutional Trust Services
                                 P.O. Box 2320
                            Dallas, Texas 75221-2320
                             Attention: Frank Ivins
 
                                        24

 
                        By Hand or by Overnight Carrier:
                           JPMorgan Chase Bank, N.A.
                          Institutional Trust Services
                          2001 Bryan Street, 9th Floor
                              Dallas, Texas 75221
                             Attention: Frank Ivins
 
                                 By Facsimile:
                        (For Eligible Institutions Only)
                                 (214) 468-6494
                             Confirm by telephone:
                                 (214) 468-6464
 
FEES AND EXPENSES
 
     We will pay the cash expenses to be incurred in connection with the
exchange offer. We will not pay brokers, dealers or others soliciting
acceptances of the exchange offer. The principal solicitation is being made by
mail. Additional solicitations, however, may be made by facsimile, e-mail, in
person or by telephone by our officers and employees.
 
     We have not retained any dealer-manager in connection with the exchange
offer and will not make any payments to broker-dealers or others soliciting
acceptances of the exchange offer. We will, however, pay the exchange agent
reasonable and customary fees for its services and reimburse it for its related
reasonable out-of-pocket expenses. We may also pay brokerage houses and other
custodians, nominees and fiduciaries the reasonable out-of-pocket expenses
incurred by them in forwarding copies of this prospectus, letters of transmittal
and related documents to the beneficial owners of the old notes and in handling
or forwarding tenders for exchange.
 
TRANSFER TAXES
 
     You will not be obligated to pay any transfer taxes in connection with a
tender of your old notes for exchange unless you instruct us to register
registered notes in the name of, or request that old notes not tendered or not
accepted in the exchange offer be returned to, a person other than the
registered tendering holder, in which event the registered tendering holder will
be responsible for the payment of any applicable transfer tax. The exchange
agent will retain possession of new notes with a face amount equal to the amount
of the transfer taxes due until it receives payment of the taxes.
 
ACCOUNTING TREATMENT
 
     We will not recognize any gain or loss for accounting purposes upon the
consummation of the exchange offer. We will amortize the expenses of the
exchange offer and the unamortized expenses related to the issuance of the old
notes over the remaining term of the registered notes.
 
                      DESCRIPTION OF THE REGISTERED NOTES
 
     We will issue the registered notes pursuant to the principal indenture,
dated as of February 4, 1997, between us and JPMorgan Chase Bank, N.A. (formerly
known as The Chase Manhattan Bank), as trustee, which we refer to as the
trustee, as supplemented by the fourth supplemental indenture dated as of August
27, 2004, under which we issued the old notes. We refer to the principal
indenture, as so supplemented, as the indenture. We refer to the old notes and
the registered notes collectively as the notes. The old notes and the registered
notes constitute the same series of notes under the indenture governing the
notes. The terms of the notes include those stated in the indenture and those
made part of the indenture by reference to the Trust Indenture Act of 1939, as
amended.
 
                                        25

 
     The following description is only a summary of the provisions of the
indenture and the registered notes that we consider material. It does not
purport to be complete, and is subject to, and is qualified in its entirety by
reference to, all of the provisions of the notes and the indenture. It does not
restate those agreements in their entirety. We urge you to read the indenture
and the form of the notes in their entirety because they, and not this
description, define your rights as holders of the notes. You can receive a copy
of the indenture upon request to us at the address or telephone number set forth
above under "Where You Can Find More Information." As used in this description,
all references to "our company" or to "we," "us" or "our" mean Diamond Offshore
Drilling, Inc., excluding, unless otherwise expressly stated or the context
otherwise requires, its subsidiaries.
 
     The registered holder of a note will be treated as the owner of it for all
purposes under the terms of the indenture. Only registered holders will have
rights under the indenture.
 
PRINCIPAL, MATURITY AND INTEREST
 
     The notes:
 
     - will be issued only in registered form without coupons in denominations
       of $1,000 and any integral multiple of $1,000 above that amount;
 
     - will be limited to $250,000,000 aggregate principal amount;
 
     - will mature on September 1, 2014; and
 
     - will accrue interest at a rate of 5.15% per year from August 27, 2004 or
       from the most recent interest payment date to which interest has been
       paid or duly provided, payable semiannually in arrears on March 1 and
       September 1 of each year, beginning March 1, 2005.
 
     Interest will be paid to the person in whose name a note is registered at
the close of business on the February 15 or August 15, as the case may be,
immediately preceding the relevant interest payment date. Interest on the notes
will be computed on the basis of a 360-day year composed of twelve 30-day
months.
 
     If any interest payment date, maturity date, redemption date or purchase
date of a note falls on a day that is not a business day, the required payment
of principal and interest will be made on the next succeeding business day as if
made on the date that the payment was due and no interest will accrue on that
payment for the period from and after that interest payment date, maturity date,
redemption date or purchase date, as the case may be, to the date of that
payment on the next succeeding business day. The term "business day" means, with
respect to any note, any day other than a Saturday, a Sunday or a day on which
banking institutions in The City of New York are authorized or required by law,
regulation or executive order to close.
 
     The notes are redeemable prior to maturity, as described below under
"-- Optional Redemption," and do not have the benefit of a sinking fund.
Principal of and interest on the notes will be payable at the office of the
paying agent, which initially will be an office or agency of the trustee, or an
office or agency maintained for such purpose, in the Borough of Manhattan, The
City of New York. The notes may be presented for registration of transfer or
exchange at the office of the registrar, each such agent initially being the
trustee. No service charge will be made for any registration of transfer or
exchange of notes, but we may require payment of a sum sufficient to cover any
tax or other governmental charge payable in connection therewith.
 
     Maturity or redemption of a note will cause interest, if any, to cease to
accrue on such note. We may not reissue a note that has matured or has been
redeemed or otherwise cancelled, except for registration of transfer, exchange
or replacement of such note.
 
RANKING OF NOTES
 
     The notes are unsecured and rank equal in right of payment to all of our
existing and future unsecured and unsubordinated indebtedness. However, we are a
holding company and, in addition to being
 
                                        26

 
subordinated to secured obligations, the notes will be effectively subordinated
to all existing and future obligations of our subsidiaries. See "Risk
Factors -- Risks Relating to the Registered Notes and the Exchange Offer -- Our
holding company structure results in substantial structural subordination and
may affect our ability to make payments on the notes." As of September 30, 2004,
we had approximately $1,176.6 million of total indebtedness outstanding. As of
September 30, 2004, our subsidiaries had approximately $24.8 million of
outstanding obligations.
 
OPTIONAL REDEMPTION
 
     The notes will be redeemable at our option, in whole at any time or in part
from time to time, on at least 15 days but not more than 60 days prior written
notice mailed to the registered holders thereof, at a redemption price equal to
the greater of (1) 100% of the principal amount of the notes to be redeemed or
(2) the sum, as determined by the Quotation Agent, as defined below, of the
present values of the principal amount of the notes to be redeemed and the
remaining scheduled payments of interest thereon from the redemption date to the
maturity date of the notes to be redeemed (excluding interest accrued to the
redemption date), which we refer to as the Remaining Life, discounted from their
respective scheduled payment dates to the redemption date on a semiannual basis
(assuming a 360-day year consisting of 30-day months) at the Treasury Rate, as
defined below, plus 20 basis points, which we refer to as the Make-Whole
Premium, plus, in either case, accrued and unpaid interest on the principal
amount of the notes redeemed to the date of redemption. If money sufficient to
pay the redemption price of and accrued interest on all of the notes (or
portions thereof) to be redeemed on the redemption date is deposited with the
trustee or paying agent on or before the redemption date and certain other
conditions are satisfied, then on and after such redemption date, interest will
cease to accrue on such notes (or such portion thereof) called for redemption.
 
     "Comparable Treasury Issue" means the U.S. Treasury security selected by
the Quotation Agent as having a maturity comparable to the Remaining Life that
would be utilized, at the time of selection and in accordance with customary
financial practice, in pricing new issues of corporate debt securities of
comparable maturity with the Remaining Life as of the applicable redemption
date.
 
     "Comparable Treasury Price" means, with respect to any redemption date, the
average of two Reference Treasury Dealer Quotations for such redemption date.
 
     "Quotation Agent" means the Reference Treasury Dealer appointed by us.
 
     "Reference Treasury Dealer" means Goldman, Sachs & Co. and its successors;
provided, however, that if the foregoing ceases to be a primary U.S. Government
securities dealer in New York City, we will substitute therefor another primary
U.S. Government securities dealer.
 
     "Reference Treasury Dealer Quotations" means, with respect to each
Reference Treasury Dealer and any redemption date, the average, as determined by
the trustee, of the bid and asked prices for the Comparable Treasury Issue
(expressed in each case as a percentage of its principal amount) quoted in
writing to the trustee by such Reference Treasury Dealer at 5:00 p.m., New York
City time, on the third business day preceding such redemption date.
 
     "Treasury Rate" means, with respect to any redemption date, the annual rate
equal to the semiannual yield to maturity of the Comparable Treasury Issue,
calculated on the third business day preceding such redemption date using a
price for the Comparable Treasury Issue (expressed as a percentage of its
principal amount) equal to the Comparable Treasury Price for such redemption
date.
 
     We may at any time, and from time to time, purchase the notes at any price
or prices in the open market or otherwise.
 
     If we decide to redeem fewer than all of the outstanding notes, the trustee
will select the notes to be redeemed in principal amounts of $1,000 or integral
multiples of $1,000. In this case, the trustee may select the notes by lot, pro
rata, or by another method the trustee considers fair and appropriate.
 
                                        27

 
CONSOLIDATION, MERGER, SALE OR CONVEYANCE
 
     The indenture provides that we may not consolidate with or merge into any
other entity or convey or transfer our properties and assets substantially as an
entirety to any entity, unless:
 
     - the successor or transferee entity, if other than us, expressly assumes
       by a supplemental indenture executed and delivered to the trustee, in
       form satisfactory to the trustee, the due and punctual payment of the
       principal of, any premium on and any interest on, all the outstanding
       notes and the performance of every covenant in the indenture to be
       performed or observed by us;
 
     - immediately after giving effect to the transaction, no Event of Default,
       as defined in the indenture, and no event which, after notice or lapse of
       time or both, would become an Event of Default, has happened and is
       continuing; and
 
     - we have delivered to the trustee an officers' certificate and an opinion
       of counsel, each in the form required by the indenture and stating that
       such consolidation, merger, conveyance or transfer and such supplemental
       indenture comply with the foregoing provisions relating to such
       transaction.
 
     In case of any such consolidation, merger, conveyance or transfer, the
successor entity will succeed to and be substituted for us as obligor on the
notes, with the same effect as if it had been named in the indenture as our
company.
 
COVENANTS
 
     The indenture contains certain covenants that will be applicable (unless
waived or amended) so long as any of the notes are outstanding.
 
     In the following discussion, when we refer to our "drilling rigs and
drillship," we mean any drilling rig or drillship (or the stock or indebtedness
of any Subsidiary, as defined in the indenture, owning such a drilling rig or
drillship) that we or one of our Subsidiaries leases as lessee, or owns greater
than a 50% interest in, that our Board of Directors deems of material importance
to us and that has a net book value greater than 2% of Consolidated Net Tangible
Assets. When we refer to "Consolidated Net Tangible Assets," we mean the total
amount of our assets (less reserves and other properly deductible items) after
deducting current liabilities (other than those that are extendable at our
option to a date more than 12 months after the date the amount is determined),
goodwill and other intangible assets shown in our most recent consolidated
balance sheet prepared in accordance with generally accepted accounting
principles.
 
  LIMITATION ON LIENS
 
     In the indenture, we have agreed that we will not create, assume or allow
to exist any debt secured by a lien upon any of our drilling rigs or drillship,
unless we secure the notes equally and ratably with the debt secured by the
lien. This covenant has exceptions that permit:
 
     - liens already existing on the date the notes are issued;
 
     - liens on property existing at the time we acquire the property or liens
       on property of a corporation or other entity at the time it becomes a
       Subsidiary;
 
     - liens securing debt incurred to finance the acquisition, completion of
       construction and commencement of commercial operation, alteration, repair
       or improvement of any property, if the debt was incurred prior to, at the
       time of or within 12 months after that event, and to the extent that debt
       is in excess of the purchase price or cost, recourse on the debt is only
       against that property;
 
     - liens securing intercompany debt;
 
                                        28

 
     - liens in favor of a governmental entity to secure either:
 
      - payments under any contract or statute; or
 
      - industrial development, pollution control or similar indebtedness;
 
     - liens imposed by law such as mechanic's or workmen's liens;
 
     - governmental liens under contracts for the sale of products or services;
 
     - liens under workers compensation laws or similar legislation;
 
     - liens in connection with legal proceedings or securing taxes or
       assessments;
 
     - good faith deposits in connection with bids, tenders, contracts or
       leases;
 
     - deposits made in connection with maintaining self-insurance, to obtain
       the benefits of laws, regulations or arrangements relating to
       unemployment insurance, old age pensions, social security or similar
       matters or to secure surety, appeal or customs bonds; and
 
     - any extensions, renewals or replacements of the above-described liens if
       both:
 
      - the amount of debt secured by the new lien does not exceed the amount of
        debt secured, plus any additional debt used to complete the project, if
        applicable; and
 
      - the new lien is limited to all or a part of the property (plus any
        improvements) secured by the original lien.
 
     In addition, without securing the notes as described above, we may create,
assume or allow to exist secured debt that this covenant would otherwise
restrict in an aggregate amount that does not exceed a "basket" equal to 10% of
our Consolidated Net Tangible Assets. When determining whether secured debt is
permitted by this exception, we must include in the calculation of the "basket"
amount all of our other secured debt that this covenant would otherwise restrict
and the present value of lease payments in connection with sale and lease-back
transactions that would be prohibited by the "Limitation on Sale and Lease-Back
Transactions" covenant described below if this exception did not apply.
 
  LIMITATION ON SALE AND LEASE-BACK TRANSACTIONS
 
     We have agreed that we will not enter into a sale and lease-back
transaction covering any drilling rig or drillship, unless one of the following
applies:
 
     - we could incur debt secured by the leased property in an amount at least
       equal to the present value of the lease payments in connection with that
       sale and lease-back transaction without violating the "Limitation on
       Liens" covenant described above; or
 
     - within six months of the effective date of the sale and lease-back
       transaction, we apply an amount equal to the present value of the lease
       payments in connection with the sale and lease-back transaction to
       either:
 
      - the acquisition of any drilling rig or drillship; or
 
      - the retirement (including by redemption, defeasement, repurchase or
        otherwise) of long-term debt or other debt maturing more than one year
        after its creation, in each case ranking equally with the notes.
 
     When we use the term "sale and lease-back transaction," we mean any
arrangement by which we sell or transfer to any person any drilling rig or
drillship that we then lease back from them. This term excludes leases no longer
than five years, intercompany leases, leases executed within 12 months of the
acquisition, construction, improvement or commencement of commercial operation
of the drilling rig or drillship, and arrangements pursuant to any provision of
law with an effect similar to the former Section 168(f)(8) of the Internal
Revenue Code of 1954 (which permitted the lessor to recognize depreciation on
the property).
                                        29

 
EVENTS OF DEFAULT; WAIVER AND NOTICE
 
     An event of default is defined in the indenture as:
 
          (a) default for 30 days in payment of any interest on the notes or in
     payment of any liquidated damages under the registration rights agreement
     described under "The Exchange Offer -- Purpose and Effect -- Registration
     Rights";
 
          (b) default in payment of principal of the notes at maturity or the
     redemption price, when the same becomes due and payable;
 
          (c) default in the payment (after any applicable grace period) of any
     indebtedness for money borrowed by our company or a Subsidiary in excess of
     $25.0 million principal amount (excluding such indebtedness of any
     Subsidiary other than a Significant Subsidiary, all the indebtedness of
     which Subsidiary is nonrecourse to our company or any other Subsidiary) or
     default on such indebtedness that results in the acceleration of such
     indebtedness prior to its express maturity, if such indebtedness is not
     discharged, or such acceleration is not annulled, by the end of a period of
     10 days after written notice to us by the trustee or to us and the trustee
     by the holders of at least 25% in principal amount of the outstanding
     notes;
 
          (d) default by us in the performance of any other covenant contained
     in the indenture for the benefit of the notes that has not been remedied by
     the end of a period of 60 days after notice is given as specified in the
     indenture; and
 
          (e) certain events of bankruptcy, insolvency and reorganization of our
     company or a Significant Subsidiary.
 
     When we refer to a "Significant Subsidiary," we mean any Subsidiary, the
Net Worth of which represents more than 10% of the Consolidated Net Worth of our
company and our Subsidiaries. The terms "Net Worth" and "Consolidated Net Worth"
are defined in the indenture.
 
     The indenture provides that:
 
     - if an event of default described in clause (a), (b), (c) or (d) above (if
       the event of default under clause (d) is with respect to less than all
       series of debt securities issued under the principal indenture and then
       outstanding) has occurred and is continuing with respect to a series of
       debt securities issued under the principal indenture and then
       outstanding, either the trustee or the holders of not less than 25% in
       aggregate principal amount of the debt securities of such series then
       outstanding (each such series acting as a separate class) may declare the
       principal (or, in the case of debt securities originally issued at a
       discount, the portion thereof that represents the issue price plus the
       accrued original issue discount where we have not previously elected to
       pay interest in cash or, if such securities have been converted to
       interest-bearing securities following a tax event, the restated principal
       amount plus accrued and unpaid interest) of the debt securities of the
       affected series and the interest accrued thereon, if any, to be due and
       payable immediately; and
 
     - if an event of default described in clause (d) above (if the event of
       default under clause (d) is with respect to all series of debt securities
       issued under the principal indenture and then outstanding) has occurred
       and is continuing, either the trustee or the holders of at least 25% in
       aggregate principal amount of all debt securities issued under the
       principal indenture and then outstanding (treated as one class) may
       declare the principal (or, in the case of the debt securities originally
       issued at a discount, the portion thereof that represents the issue price
       plus the accrued original issue discount where we have not previously
       elected to pay interest in cash or, if such securities have been
       converted to interest-bearing securities following a tax event, the
       restated principal amount plus accrued and unpaid interest) of all debt
       securities issued under the principal indenture and then outstanding and
       the interest accrued thereon, if any, to be due and payable immediately,
 
                                        30

 
but upon certain conditions such declarations may be annulled and past defaults
(except for defaults in the payment of principal of, any premium on or any
interest on, such debt securities and in compliance with certain covenants) may
be waived by the holders of a majority in aggregate principal amount of the debt
securities of such series then outstanding. If an event of default described in
clause (e) occurs and is continuing, then the principal amount (or, in the case
of debt securities originally issued at a discount, such portion of the
principal amount that represents the issue price plus the accrued original issue
discount where we have not previously elected to pay interest in cash or, if
such securities have been converted to interest-bearing securities following a
tax event, the restated principal amount plus accrued and unpaid interest) of
all the debt securities issued under the principal indenture and then
outstanding and all accrued interest thereon shall become and be due and payable
immediately, without any declaration or other act by the trustee or any other
holder.
 
     Under the indenture the trustee must give to the holders of notes notice of
all uncured defaults known to it with respect to the notes within 90 days after
such a default occurs (the term default to include the events specified above
without notice or grace periods); provided that, except in the case of default
in the payment of principal of, any premium on or any interest on, any of the
notes, or default in the payment of any sinking or purchase fund installment or
analogous obligations, the trustee will be protected in withholding such notice
if it in good faith determines that the withholding of such notice is in the
interests of the holders of the notes.
 
     No holder of any notes may institute any action under the indenture unless:
 
     - such holder has given the trustee written notice of a continuing event of
       default with respect to the notes;
 
     - the holders of not less than 25% in aggregate principal amount of the
       notes then outstanding have requested the trustee to institute
       proceedings in respect of such event of default;
 
     - such holder or holders have offered the trustee such reasonable indemnity
       as the trustee may require;
 
     - the trustee has failed to institute an action for 60 days thereafter; and
 
     - no inconsistent direction has been given to the trustee during such
       60-day period by the holders of a majority in aggregate principal amount
       of notes.
 
     The holders of a majority in aggregate principal amount of the notes
affected and then outstanding will have the right, subject to certain
limitations, to direct the time, method and place of conducting any proceeding
for any remedy available to the trustee or exercising any trust or power
conferred on the trustee with respect to the notes. The indenture provides that,
if an event of default occurs and is continuing, the trustee, in exercising its
rights and powers under the indenture, will be required to use the degree of
care of a prudent man in the conduct of his own affairs. The indenture further
provides that the trustee shall not be required to expend or risk its own funds
or otherwise incur any financial liability in the performance of any of its
duties under the indenture unless it has reasonable grounds for believing that
repayment of such funds or adequate indemnity against such risk or liability is
reasonably assured to it.
 
     We must furnish to the trustee within 120 days after the end of each fiscal
year a statement signed by one of certain officers of our company to the effect
that a review of our activities during such year and of our performance under
the indenture and the terms of the notes has been made, and, to the best of the
knowledge of the signatories based on such review, we have complied with all
conditions and covenants of the indenture or, if we are in default, specifying
such default.
 
     For the purposes of determining whether the holders of the requisite
principal amount of notes have taken any action herein described, the principal
amount of notes will be deemed to be the portion of such principal amount that
would be due and payable at the time of the taking of such action upon a
declaration of acceleration of maturity thereof.
 
                                        31

 
MODIFICATION OF THE INDENTURE
 
     We and the trustee may, without the consent of the holders of the debt
securities issued under the principal indenture, enter into supplemental
indentures for, among others, one or more of the following purposes:
 
     - to evidence the succession of another corporation to our company, and the
       assumption by such successor of our obligations under the indenture and
       the debt securities of any series;
 
     - to add covenants of our company, or surrender any rights of our company,
       for the benefit of the holders of debt securities of any or all series;
 
     - to cure any ambiguity, omission, defect or inconsistency in such
       indenture;
 
     - to establish the form or terms of any series of debt securities,
       including any subordinated securities;
 
     - to evidence and provide for the acceptance of any successor trustee with
       respect to one or more series of debt securities or to facilitate the
       administration of the trusts thereunder by one or more trustees in
       accordance with such indenture; and
 
     - to provide any additional events of default.
 
     With certain exceptions, the indenture or the rights of the holders of the
notes may be modified by us and the trustee with the consent of the holders of a
majority in aggregate principal amount of the notes then outstanding, but no
such modification may be made without the consent of the holder of each
outstanding note affected thereby that would:
 
     - change the maturity of any payment of principal of, or any premium on, or
       any installment of interest on any note, or reduce the principal amount
       thereof or the rate of regular interest or any premium thereon, or change
       the method of computing the amount of principal thereof or the rate of
       interest thereon on any date or change any place of payment where, or the
       coin or currency in which, any note or any premium or interest thereon is
       payable, or impair the right to institute suit for the enforcement of any
       such payment on or after the maturity thereof (or, in the case of
       redemption or repayment, on or after the redemption date or the repayment
       date, as the case may be) or adversely affect the repurchase or
       redemption provisions in the indenture;
 
     - reduce the percentage in principal amount of the outstanding notes, the
       consent of whose holders is required for any such modification, or the
       consent of whose holders is required for any waiver of compliance with
       certain provisions of the indenture or certain defaults thereunder and
       their consequences provided for in the indenture; or
 
     - modify any of the provisions of certain sections of the indenture,
       including the provisions summarized in this paragraph, except to increase
       any such percentage or to provide that certain other provisions of the
       indenture cannot be modified or waived without the consent of the holder
       of each outstanding note affected thereby.
 
DISCHARGE OF THE INDENTURE
 
     We may satisfy and discharge our obligations under the indenture by
delivering to the trustee for cancellation all outstanding notes or by
depositing with the trustee or the paying agent, if applicable, after the notes
have become due and payable, whether at stated maturity, or any redemption date
or otherwise, cash sufficient to pay all of the outstanding notes and paying all
other sums payable under the indenture by our company.
 
GOVERNING LAW
 
     The indenture and the notes will be governed by and construed in accordance
with the laws of the State of New York.
 
                                        32

 
FORM, DENOMINATION, TRANSFER, EXCHANGE AND BOOK-ENTRY PROCEDURES
 
     We will issue notes only in fully registered form, without interest
coupons, in denominations of $1,000 and integral multiples of $1,000. We will
not issue notes in bearer form.
 
  GLOBAL NOTES
 
     The registered notes initially will be represented by one or more notes in
registered, global form without interest coupons, which we refer to as the
global notes. We will deposit the global notes upon issuance with the trustee as
custodian for DTC in New York, New York, and register the global notes in the
name of DTC or its nominee, in each case for credit to an account of a direct or
indirect participant in DTC as described below.
 
     Except as set forth below, the global notes may be transferred, in whole
and not in part, only to another nominee of DTC or to a successor of DTC or its
nominee. You may not exchange your beneficial interest in the Global Notes for
Notes in certificated form except in the limited circumstances described below
under "-- Exchanges of Book-Entry Notes for Certificated Notes."
 
  EXCHANGES OF BOOK-ENTRY NOTES FOR CERTIFICATED NOTES
 
     You may not exchange your beneficial interest in a global note for a note
in certificated form unless:
 
     - DTC (a) notifies us that it is unwilling or unable to continue as
       depository for the global note or (b) has ceased to be a clearing agency
       registered under the Exchange Act, and in either case we thereupon fail
       to appoint a successor depository;
 
     - we at any time and in our sole discretion determine not to have notes
       represented by a global note; or
 
     - an Event of Default shall have occurred and be continuing with respect to
       the notes.
 
     In all cases, certificated notes delivered in exchange for any global note
or beneficial interests therein will be registered in the names, and issued in
any approved denominations, requested by or on behalf of the depository (in
accordance with its customary procedures).
 
  CERTAIN BOOK-ENTRY PROCEDURES
 
     The description of the operations and procedures of DTC that follows is
provided solely as a matter of convenience. These operations and procedures are
solely within their control and are subject to changes by them from time to
time. We take no responsibility for these operations and procedures and urge you
to contact the system or their participants directly to discuss these matters.
 
     DTC has advised us that DTC is a limited purpose trust company organized
under the laws of the State of New York, a member of the Federal Reserve System,
a "clearing corporation" within the meaning of the Uniform Commercial Code and a
"Clearing Agency" registered pursuant to the provisions of Section 17A of the
Exchange Act. DTC was created to hold securities for its participating
organizations, or participants, and facilitate the clearance and settlement of
securities transactions between participants through electronic book-entry
changes in accounts of its participants, thereby eliminating the need for
physical transfer and delivery of certificates. Participants include securities
brokers and dealers, banks, trust companies and clearing corporations and may
include certain other organizations. Indirect access to the DTC system is
available to other entities such as banks, brokers, dealers and trust companies
that clear through or maintain a custodial relationship with a participant,
either directly or indirectly, which we refer to as indirect participants.
 
     DTC has advised us that its current practice, upon the issuance of the
global notes, is to credit, on its internal system, the respective principal
amount of the individual beneficial interests represented by such global notes
to the accounts with DTC of the participants through which such interests are to
be held. Ownership of beneficial interests in the global notes will be shown on,
and the transfer of that ownership
 
                                        33

 
will be effected only through, records maintained by DTC or its nominees (with
respect to interests of participants).
 
     AS LONG AS DTC, OR ITS NOMINEE, IS THE REGISTERED HOLDER OF A GLOBAL NOTE,
DTC OR SUCH NOMINEE, AS THE CASE MAY BE, WILL BE CONSIDERED THE SOLE OWNER AND
HOLDER OF THE NOTES REPRESENTED BY SUCH GLOBAL NOTE FOR ALL PURPOSES UNDER THE
INDENTURE AND THE NOTES. Except in the limited circumstances described above
under "-- Exchanges of Book-Entry Notes for Certificated Notes," you will not be
entitled to have any portions of a global note registered in your name, will not
receive or be entitled to receive physical delivery of notes in definitive form
and will not be considered the owner or holder of a global note (or any note
represented thereby) under the indenture governing the notes.
 
     You may hold your interests in the global notes directly through DTC, if
you are a participant in such system, or indirectly through organizations which
are participants in such system. All interests in a global note will be subject
to the procedures and requirements of DTC.
 
     The laws of some states require that certain persons take physical delivery
in definitive form of securities that they own. Consequently, your ability to
transfer your beneficial interests in a global note to such persons may be
limited to that extent. Because DTC can act only on behalf of its participants,
which in turn act on behalf of indirect participants and certain banks, your
ability to pledge your interests in a global note to persons or entities that do
not participate in the DTC system, or otherwise take actions in respect of such
interests, may be affected by the lack of a physical certificate evidencing such
interests.
 
     We will make payments of the principal of, premium, if any, and interest on
global notes to DTC or its nominee as the registered owner thereof. Neither we
nor the trustee nor any of our or their respective agents will have any
responsibility or liability for any aspect of the records relating to or
payments made on account of beneficial ownership interests in the global notes
or for maintaining, supervising or reviewing any records relating to such
beneficial ownership interests.
 
     We expect that DTC or its nominee, upon receipt of any payment of principal
or interest in respect of a global note representing any notes held by it or its
nominee, will immediately credit participants' accounts with payments in amounts
proportionate to their respective beneficial interests in the principal amount
of such global note for such notes as shown on the records of DTC or its
nominee. We also expect that payments by participants to owners of beneficial
interests in such global note held through such participants will be governed by
standing instructions and customary practices, as is now the case with
securities held for the accounts of customers registered in "street name." Such
payment will be the responsibility of such participants.
 
     Interests in the global notes will trade in DTC's settlement system, and
secondary market trading activity in such interests will therefore settle in
immediately available funds, subject in all cases to the rules and procedures of
DTC and its participants. Transfers between participants in DTC will be effected
in accordance with DTC's procedures, and will be settled in same-day funds.
 
     DTC has advised us that DTC will take any action permitted to be taken by a
holder of notes (including the presentation of notes for exchange as described
below) only at the direction of one or more participants to whose account with
DTC interests in the global notes are credited and only in respect of such
portion of the aggregate principal amount of the notes as to which such
participant or participants has or have given such direction. However, if there
is an Event of Default under the notes, DTC reserves the right to exchange the
global notes for legended notes in certificated form, and to distribute such
notes to DTC's participants.
 
     Although DTC has agreed to the foregoing procedures in order to facilitate
transfers of beneficial ownership interests in the global notes among
participants of DTC, it is under no obligation to perform or continue to perform
such procedures, and such procedures may be discontinued at any time. Neither
we, the trustee nor any of our or their respective agents will have any
responsibility for the performance by DTC, its participants or indirect
participants of their respective obligations under the rules and procedures
governing their operations, including maintaining, supervising or reviewing the
records relating to, or payments made on account of, beneficial ownership
interests in global notes.
                                        34

 
             CERTAIN UNITED STATES FEDERAL INCOME TAX CONSEQUENCES
 
     The following is a summary of the material United States federal income tax
consequences relating to the exchange of an old note for a registered note in
the exchange offer. It does not contain a complete analysis of all the potential
tax considerations relating to the exchange. In addition, this summary is
limited to a beneficial owner of an old note who holds the old note, and will
hold the registered note, as a "capital asset" within the meaning of Section
1221 of the Internal Revenue Code of 1986, as amended, or the Code. In general,
a "capital asset" is an asset held for investment.
 
     The discussion below is based upon the provisions of the Code, existing and
proposed Treasury regulations promulgated under the Code, and rulings, judicial
decisions and administrative interpretations under the Code, as of the date of
this prospectus. Those authorities may be changed, perhaps retroactively, so as
to result in United States federal income tax consequences different from those
discussed below.
 
     For United States federal income tax purposes, the exchange of an old note
for a registered note in the exchange offer will not constitute a taxable event.
Accordingly, the exchange offer should have no United States federal income tax
consequences to you. There will be no change in your tax basis and your holding
period will carry over to the registered notes, and the United States federal
income tax consequences of owning and disposing of the registered notes will be
the same as those applicable to the old notes.
 
     The preceding discussion of United States federal income tax consequences
of the exchange offer is for general information only and is not tax advice.
Accordingly, each investor should consult its own tax advisor as to the
particular tax consequences to it of exchanging an old note for a registered
note, including the applicability and effect of any state, local or foreign tax
laws and of any proposed changes in applicable laws.
 
                              PLAN OF DISTRIBUTION
 
     Broker-dealers that acquired the old notes tendered by them in exchange for
registered notes directly from us may not resell the registered notes unless
they have been registered for resale under the Securities Act or are resold in
compliance with an applicable exemption from the registration requirements of
the Securities Act. Broker-dealers that acquired old notes as a result of
market-making or other trading activities and received registered notes for
their own account in exchange for those old notes must acknowledge that they
will deliver a prospectus in connection with any resale of those registered
notes. This prospectus, as it may be amended or supplemented from time to time,
may be used by a broker-dealer in connection with resales of registered notes
received in exchange for old notes, where those old notes were acquired as a
result of market-making activities or other trading activities. We have agreed
that, for a period of 180 days after the time of expiration, we will make this
prospectus, as amended or supplemented, available to any broker-dealer for use
in connection with such resales by that broker-dealer.
 
     We will not receive any proceeds from any sale of registered notes by
broker-dealers. Registered notes received by broker-dealers for their own
account pursuant to the exchange offer may be sold from time to time in one or
more transactions in the over-the-counter market, in negotiated transactions,
through the writing of options on the registered notes or a combination of these
methods of resale, at market prices prevailing at the time of resale, at prices
related to the prevailing market prices or negotiated prices. Any resale by a
broker-dealer may be made directly to purchasers or to or through brokers or
dealers who may receive compensation in the form of commissions or concessions
from that broker-dealer or the purchasers of any registered notes. Any
broker-dealer that resells registered notes that were received by it for its own
account pursuant to the exchange offer and any broker or dealer that
participates in a distribution of the registered notes may be deemed to be an
"underwriter" within the meaning of the Securities Act and any profit on any
resale of those registered notes and any commission or concessions received by
any of those persons may be deemed to be underwriting compensation under the
Securities Act. The letter of
 
                                        35

 
transmittal states that, by acknowledging that it will deliver and by delivering
a prospectus, a broker-dealer will not be deemed to admit that it is an
"underwriter" within the meaning of the Securities Act.
 
     For a period of 180 days after the time of expiration we will promptly send
additional copies of this prospectus and any amendment or supplement to this
prospectus to any broker-dealer that requests those documents in the letter of
transmittal. We have agreed to pay all expenses incident to our performance of,
or compliance with, the registration rights agreement other than agency fees and
commissions attributable to the sale of notes, and we will indemnify the holders
of the notes, including any broker-dealers, against specified liabilities,
including liabilities under the Securities Act, as provided in the registration
rights agreement.
 
                                 LEGAL MATTERS
 
     The validity of the registered notes will be passed upon for us by Duane
Morris LLP, Houston, Texas.
 
                                    EXPERTS
 
     The consolidated financial statements incorporated in this prospectus by
reference from Diamond Offshore Drilling, Inc.'s Annual Report on Form 10-K for
the year ended December 31, 2003 have been audited by Deloitte & Touche LLP, an
independent registered public accounting firm, as stated in their report (which
report expresses an unqualified opinion and includes an explanatory paragraph
referring to Diamond Offshore Drilling, Inc.'s change in method of accounting
for goodwill in 2002 to conform to the adoption of Statement of Financial
Accounting Standards No. 142), which is incorporated herein by reference, and
have been so incorporated in reliance upon the report of such firm given upon
their authority as experts in accounting and auditing.
 
                                        36

 
     NO PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATIONS OTHER THAN THOSE CONTAINED IN THIS PROSPECTUS AND, IF GIVEN OR
MADE, SUCH INFORMATION AND REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING
BEEN AUTHORIZED. THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL OR THE
SOLICITATION OF AN OFFER TO BUY ANY SECURITIES OTHER THAN THE SECURITIES TO
WHICH IT RELATES OR ANY OFFER TO SELL OR THE SOLICITATION OF AN OFFER TO BUY
SUCH SECURITIES IN ANY CIRCUMSTANCES IN WHICH SUCH OFFER OR SOLICITATION IS
UNLAWFUL. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY SALE MADE HEREUNDER
SHALL, UNDER ANY CIRCUMSTANCES, CREATE ANY IMPLICATION THAT THERE HAS BEEN NO
CHANGE IN THE AFFAIRS OF OUR COMPANY SINCE THE DATE OF THIS PROSPECTUS OR THAT
THE INFORMATION CONTAINED IN THIS PROSPECTUS IS CORRECT AS OF ANY TIME
SUBSEQUENT TO ITS DATE.
 
                             ---------------------
 
                               TABLE OF CONTENTS
 

                                       
Where You Can Find More Information.....    i
Prospectus Summary......................    1
Risk Factors............................    8
Special Note Regarding Forward-Looking
  Statements............................   12
Use of Proceeds.........................   14
Ratio of Earnings to Fixed Charges......   15
Selected Consolidated Financial Data....   16
The Exchange Offer......................   16
Description of the Registered Notes.....   25
Certain United States Federal Income Tax
  Consequences..........................   35
Plan of Distribution....................   35
Legal Matters...........................   36
Experts.................................   36

 
     EACH BROKER-DEALER WHO HOLDS OLD NOTES ACQUIRED FOR ITS OWN ACCOUNT AS A
RESULT OF MARKET-MAKING OR OTHER TRADING ACTIVITIES AND WHO RECEIVES REGISTERED
NOTES FOR ITS OWN ACCOUNT IN EXCHANGE FOR SUCH OLD NOTES PURSUANT TO THE
EXCHANGE OFFER MUST DELIVER A COPY OF THIS PROSPECTUS IN CONNECTION WITH ANY
RESALE OF SUCH REGISTERED NOTES.
 
                                  $250,000,000
 
                     (DIAMOND OFFSHORE DRILLING, INC. LOGO)
                                DIAMOND OFFSHORE
                                 DRILLING, INC.
                    OFFER TO EXCHANGE ALL OF THE OUTSTANDING
                    5.15% SENIOR NOTES DUE SEPTEMBER 1, 2014
 
                                      FOR
 
                    5.15% SENIOR NOTES DUE SEPTEMBER 1, 2014
                  REGISTERED UNDER THE SECURITIES ACT OF 1933
                            -----------------------
 
                                   PROSPECTUS
                            -----------------------
                               FEBRUARY 11, 2005