EXHIBIT 99.1
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FOR IMMEDIATE RELEASE                                      CONTACT: LES VAN DYKE
                                                    DIRECTOR, INVESTOR RELATIONS
                                                                  (281) 492-5370

                    DIAMOND OFFSHORE DRILLING, INC. ANNOUNCES
                 LETTER OF INTENT TO CONSTRUCT TWO JACK-UP RIGS

Houston, TX, May 2, 2005 -- Diamond Offshore Drilling, Inc. (NYSE:DO) today
announced that the Company has entered into a letter of intent with Keppel FELS
Limited in Singapore for construction of two high-performance premium jack-up
rigs. The units, one to be constructed in Singapore, and the other in
Brownsville, TX, are expected to have an aggregate cost of approximately $300
million, including spares, commissioning, site supervision and other costs the
Company may incur during the course of construction.

Both rigs will be 350-ft. KFELS MOD V B-Class (Super) design, capable of
drilling depths of up to 35,000 ft. with a hook load capacity of 2 million
pounds and a cantilever reach of 70 ft. Delivery of both units is anticipated in
the first quarter of 2008. The letter of intent also provides an option for
construction of a third jack-up rig at a later date. The transaction is subject
to execution of a definitive construction contract.

Diamond Offshore President and Chief Operating Officer, Larry Dickerson, said
"The primary focus of the Company has been enhancing our deepwater rigs, while
at the same time we have significantly modernized our jack-up fleet. Based on
the strength of the market, we believe the construction of these premium jack-up
units will augment our ability to offer a full range of services to our
customers."

Diamond Offshore provides contract drilling services to the energy industry
around the globe and is a leader in deepwater drilling. The Company's fleet of
45 offshore drilling rigs consists of 30 semisubmersibles, 14 jack-ups and one
drillship.

Statements in this press release may contain "forward-looking statements"
within the meaning of Section 27A of the Securities Act of 1933, as amended, and
Section 21E of the Securities Exchange Act of 1934, as amended. Such statements
include, but are not limited to, statements concerning construction costs,
expected delivery dates, the construction option, execution of definitive
construction contracts, and market conditions. Such statements are inherently
subject to a variety of risks and uncertainties that could cause actual results
to differ materially from those anticipated or projected, including the risk
that the letter of intent may not result in a binding contract, potential
construction of a rig may not materialize, delays in construction or cost
overruns may occur, and that the present favorable markets for the Company's
services will not be maintained, or may not continue to improve. A discussion of
additional risk factors that could impact these areas and the Company's overall
business and financial performance can be found in the

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Company's reports and other filings with the Securities and Exchange
Commission. These factors include, among others, general economic and business
conditions, casualty losses, industry fleet capacity, changes in foreign and
domestic oil and gas exploration and production activity, competition, changes
in foreign, political, social and economic conditions, regulatory initiatives
and compliance with governmental regulations, customer preferences and various
other matters, many of which are beyond the Company's control. Given these
concerns, investors and analysts should not place undue reliance on
forward-looking statements. Each forward-looking statement speaks only as of the
date of this press release. The Company expressly disclaims any obligation or
undertaking to release publicly any updates or revisions to any forward-looking
statement to reflect any change in the Company's expectations with regard
thereto or any change in events, conditions or circumstances on which any
forward-looking statement is based.
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