.
.
.
EXHIBIT 99.1
1
DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF MAY 9, 2005
<Table>
<Caption>
RIG NAME WD DESIGN LOCATION STATUS* OPERATOR CURRENT TERM DAYRATE (000S)
- ---------------------------------------------------------------------------------------------------------------------------
DOMESTIC DEEPWATER SEMISUBMERSIBLES (6)
- ---------------------------------------------------------------------------------------------------------------------------
Ocean Quest 3,500' Victory Class GOM Contracted Noble one well high 110's
- ---------------------------------------------------------------------------------------------------------------------------
Ocean Star 5,500' Victory Class GOM Contracted Kerr-McGee 220 day extension mid 70's
- ---------------------------------------------------------------------------------------------------------------------------
Ocean America 5,500' Ocean Odyssey GOM Contracted Pioneer three wells low 150's
- ---------------------------------------------------------------------------------------------------------------------------
Ocean Valiant 5,500' Ocean Odyssey GOM Contracted Kerr-McGee one well mid 80's
- ---------------------------------------------------------------------------------------------------------------------------
Ocean Victory 5,500' Victory Class GOM Contracted Shell 100 day term low 130's
- ---------------------------------------------------------------------------------------------------------------------------
Ocean Confidence 7,500' DP Aker H- GOM Contracted BP five-year term mid 170's
3.2 Modified
- ---------------------------------------------------------------------------------------------------------------------------
DOMESTIC 2ND/3RD GENERATION SEMISUBMERSIBLES (4)
- ---------------------------------------------------------------------------------------------------------------------------
Ocean Voyager 2,000' Victory Class GOM Contracted ATP two wells mid 90's
- ---------------------------------------------------------------------------------------------------------------------------
Ocean Concord 2,200' F&G SS-2000 GOM Contracted Kerr-McGee one well upper 50's
- ---------------------------------------------------------------------------------------------------------------------------
Ocean Lexington 2,200' F&G SS-2000 GOM Contracted Walter Oil & Gas three wells mid 50's
- ---------------------------------------------------------------------------------------------------------------------------
Ocean Saratoga 2,200' F&G SS-2000 GOM Contracted LLOG three wells mid 60's
</Table>
<Table>
<Caption>
EST. END
RIG NAME START DATE DATE FUTURE CONTRACTS AND OTHER INFORMATION
- ---------------------------------------------------------------------------------------------------------------------
DOMESTIC DEEPWATER SEMISUBMERSIBLES (6)
- ---------------------------------------------------------------------------------------------------------------------
Ocean Quest late April 2005 late May 2005 120 day term plus option with Noble in mid 120's beginning
late May and ending late Sept. 2005. Available; actively
marketing.
- ---------------------------------------------------------------------------------------------------------------------
Ocean Star early Dec. 2004 mid July 2005 90 day term extension plus option with Kerr-McGee in low
140's beginning mid July 2005 and ending early Oct. 2005;
followed by 12 month extension with Kerr-McGee in mid 170's
beginning early Oct. 2005 and ending early Oct. 2006.
Available; actively marketing.
- ---------------------------------------------------------------------------------------------------------------------
Ocean America early May 2005 late Aug. 2005 Following assignment wells with Pioneer, first of two
extension wells with Mariner in mid 110's beginning late
Aug. and ending mid Oct.; followed by second well with
Mariner in low 130's beginning mid Oct. and ending mid Nov.
2005. Available; actively marketing.
- ---------------------------------------------------------------------------------------------------------------------
Ocean Valiant late Jan. 2005 mid May 2005 One well with Kerr-McGee in high 90's beginning mid May and
ending late July, followed by one well with Kerr-McGee in
low 130's beginning late July and ending late Sept. 2005;
followed by 180 day term extension with Kerr-McGee in low
150's beginning late Sept. 2005 and ending late Mar. 2006.
Available; actively marketing.
- ---------------------------------------------------------------------------------------------------------------------
Ocean Victory mid Feb. 2005 late May 2005 Available; actively marketing.
- ---------------------------------------------------------------------------------------------------------------------
Ocean Confidence early Jan. 2001 early Jan. 2006 Available; actively marketing.
- ---------------------------------------------------------------------------------------------------------------------
DOMESTIC 2ND/3RD GENERATION SEMISUBMERSIBLES (4)
- ---------------------------------------------------------------------------------------------------------------------
Ocean Voyager early May 2005 late July 2005 One well with Kerr-McGee in low 110's beginning late July
and ending mid Sept.; followed by one well with Amerada Hess
in low 110's beginning mid Sept. and ending early Nov.;
followed by LOI for one well in low 110's beginning early
Nov. and ending late Dec.; followed by two wells plus option
with Amerada Hess in mid 120's beginning late Dec. 2005 and
ending late Mar. 2006. Available; actively marketing.
- ---------------------------------------------------------------------------------------------------------------------
Ocean Concord mid April 2005 mid May 2005 One well with Amerada Hess in mid 120's beginning mid May
and ending early Aug.; followed by one well with Kerr-McGee
in mid 70's beginning late Aug. and ending early Oct.;
followed by two well extension plus option with Kerr-McGee
in mid 90's beginning early Oct. and ending mid Dec.
Available; actively marketing.
- ---------------------------------------------------------------------------------------------------------------------
Ocean Lexington late Jan. 2005 late May 2005 Rig will go in for approximately 90-day Survey and
maintenance between second and third well, beginning late
May and ending mid Aug. Following survey, two additional
wells with Walter in low 60's beginning mid Aug. and ending
mid Oct.; followed by one well plus option with Walter in
low 80's beginning mid Oct. and ending mid Nov. 2005.
Available; actively marketing.
- ---------------------------------------------------------------------------------------------------------------------
Ocean Saratoga mid Dec. 2004 mid June 2005 Two wells plus option with LLOG in low 110's beginning mid
June and ending early Nov.; followed by six month extension
with LLOG in low 120's beginning early Nov. 2005 and ending
early May 2006. Available; actively marketing.
</Table>
2
DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF MAY 9, 2005
<Table>
<Caption>
RIG NAME WD DESIGN LOCATION STATUS* OPERATOR CURRENT TERM DAYRATE (000S)
- ---------------------------------------------------------------------------------------------------------------------------------
DOMESTIC JACKUPS (12)
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Crusader 200' Mat Cantilever GOM Contracted Walter Oil & Gas two well extension mid 30's
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Drake 200' Mat Cantilever GOM Contracted ADTI/Seneca three wells plus option mid 40's
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Champion 250' Mat Slot GOM Contracted Hunt two wells low 40's
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Columbia 250' Independent Leg GOM Contracted Kerr-McGee Five wells mid 40's
Cantilever
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Spartan 300' Independent Leg GOM Contracted LLOG three wells plus option high 40's
Cantilever
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Spur 300' Independent Leg GOM Contracted Spinnaker one well mid 40's
Cantilever
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean King 300' Independent Leg GOM Contracted El Paso three wells plus option mid 50's
Cantilever
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Nugget 300' Independent Leg GOM Contracted Mariner one well low 50's
Cantilever
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Summit 300' Independent Leg GOM Contracted LLOG two wells plus option mid 40's
Cantilever
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Warwick 300' Independent Leg GOM Contracted Chevron/Texaco 90 day term mid 50's
Cantilever
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Titan 350' Independent Leg GOM Contracted BHP one well plus option mid 50's
Cantilever
- ---------------------------------------------------------------------------------------------------------------------------------
Ocean Tower 350' Independent Leg GOM Contracted Chevron/Texaco one well plus option mid 50's
Cantilever
</Table>
<Table>
<Caption>
EST. END
RIG NAME START DATE DATE FUTURE CONTRACTS AND OTHER INFORMATION
- ----------------------------------------------------------------------------------------------------------------------
DOMESTIC JACKUPS (12)
- ----------------------------------------------------------------------------------------------------------------------
Ocean Crusader late Jan. 2005 late May 2005 Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Drake early May 2005 early June 2005 Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Champion late Jan. 2005 early June 2005 One well extension plus option with Hunt in mid 40's
beginning early June and ending late July 2005. Available;
actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Columbia early Jan. 2005 mid June 2005 Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Spartan late Feb. 2005 late June 2005 Two well extension plus option with LLOG in high 50's
beginning late June and ending late Aug. 2005. Available;
actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Spur mid Dec. 2004 mid May 2005 One well with Forest in mid 40's beginning mid May and
ending late June 2005. Maintenance/repairs late June through
late Aug. 2005. Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean King early Mar. 2005 early June 2005 One well extension with El Paso in mid 50's beginning early
June and ending early July 2005. Available; actively
marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Nugget early April 2005 mid May 2005 Two wells plus option with Houston Exploration in low 50's
beginning mid May and ending late Aug. 2005. Available;
actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Summit late Feb. 2005 early June 2005 One well extension plus option with LLOG in high 50's
beginning early June and ending early July 2005. Available;
actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Warwick mid Mar. 2005 late May 2005 Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Titan late Jan. 2005 late June 2005 Three wells with Walter in mid 70's beginning late June and
ending late Sept. Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Tower early Jan. 2005 mid Aug. 2005 One well extension plus option with Chevron/Texaco in high
60's beginning mid Aug. and ending early Nov. 2005.
Available; actively marketing.
</Table>
3
DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF MAY 9, 2005
<Table>
<Caption>
CURRENT
RIG NAME WD DESIGN LOCATION STATUS* OPERATOR TERM DAYRATE (000S)
- ------------------------------------------------------------------------------------------------------------------------------
INTERNATIONAL SEMISUBMERSIBLES (17)
- ------------------------------------------------------------------------------------------------------------------------------
MEXICO
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Ambassador 1,100' Bethlehem SS-2000 GOM Contracted PEMEX four year term work mid 50's
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Whittington 1,500' Aker H-3 GOM Contracted PEMEX four year term work low 60's
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Worker 3,500' F&G 9500 Enhanced GOM Contracted PEMEX four year term work high 60's
Pacesetter
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Yorktown 2,850' F&G SS-2000 GOM Contracted PEMEX four year term work mid 40's
- ------------------------------------------------------------------------------------------------------------------------------
NORTH SEA
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Nomad 1,200' Aker H-3 North Sea Contracted Talisman one year low 80's
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Guardian 1,500' Earl & Wright Sedco North Sea Contracted Shell one year low 80's
711 Series
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Princess 1,500' Aker H-3 North Sea Contracted Talisman one year extension low 80's
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Vanguard 1,500' Bingo 3000 North Sea Contracted ENI Standby mid 130's
- ------------------------------------------------------------------------------------------------------------------------------
AUSTRALASIA
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Bounty 1,500' Victory Class Australia Contracted ENI one well plus option mid 80's
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Patriot 1,500' Bingo 3000 Australia Contracted Santos two wells high 70's
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Epoch 1,640' Korkut Malaysia Contracted Murphy six wells plus option mid 70's
- ------------------------------------------------------------------------------------------------------------------------------
Ocean General 1,640' Korkut Viet Nam Contracted KNOC two wells mid 50's
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Baroness 7,000' Victory Class Indonesia Contracted Unocal 180 day extension mid 130's
- ------------------------------------------------------------------------------------------------------------------------------
Ocean Rover 7,000' Victory Class Malaysia Contracted Murphy six option wells low 120's
</Table>
<Table>
<Caption>
EST. END
RIG NAME START DATE DATE FUTURE CONTRACTS AND OTHER INFORMATION
- ----------------------------------------------------------------------------------------------------------------------
INTERNATIONAL SEMISUBMERSIBLES (17)
- ----------------------------------------------------------------------------------------------------------------------
MEXICO
- ----------------------------------------------------------------------------------------------------------------------
Ocean Ambassador late July 2003 mid Dec. 2007 Available.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Whittington late July 2003 early Oct. 2006 Available.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Worker mid Aug. 2003 late July 2007 Available.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Yorktown late Oct. 2003 mid July 2007 Available.
- ----------------------------------------------------------------------------------------------------------------------
NORTH SEA
- ----------------------------------------------------------------------------------------------------------------------
Ocean Nomad early Jan. 2005 early Jan. 2006 Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Guardian late Mar. 2005 late Mar. 2006 Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Princess early Jan. 2005 late Dec. 2005 Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Vanguard early May 2005 mid May 2005 One year plus option program in Norway with Statoil in low
140's beginning in mid May 2005 and ending in early Aug.
2006 (time period to include one well redrill with ENI in
low 140's beginning late July and ending early Nov. 2005).
Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
AUSTRALASIA
- ----------------------------------------------------------------------------------------------------------------------
Ocean Bounty early April 2005 mid May 2005 One well plus option with ConocoPhillips in mid 80's
beginning mid May and ending early Aug.; followed by one
well with Coogee Res. in mid 80's beginning early Aug. and
ending early Sept.; followed by LOI for two wells plus
option in low 90's beginning early Sept. and ending mid
Nov.; followed by LOI for one well plus option in mid 90's
beginning mid Nov. and ending mid Dec.; followed by LOI for
four wells plus option in high 90's beginning mid Dec. 2005
and ending mid June 2006. Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Patriot late April 2005 early July 2005 One well plus three options with Anzon in high 70's
beginning early July and ending mid Aug.; followed by one
well with Santos in high 70's beginning mid Aug. and ending
mid Sept. 2005; followed by one well with Bass Straits in
high 70's beginning mid Sept. and ending early Oct.;
followed by LOI for one well in high 130's beginning early
Oct. and ending mid Oct.; followed by first of four Anzon
options in mid 130's beginning mid Oct. and ending late
Nov.; followed by second of four Anzon options in upper
130's beginning late Nov. and ending late Dec.; followed by
third and fourth of four options in low 140's beginning late
Dec. 2005 and ending early Mar. 2006 Available; actively
marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Epoch late April 2005 mid Jan. 2006 Available; actively marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean General early April 2005 early June 2005 LOI for four wells plus option in mid 70's in Malaysia
beginning early June and ending late Oct.; followed by LOI
for one well plus option in high 70's in Viet Nam beginning
late Oct. and ending early Dec. 2005. Available; actively
marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Baroness late Dec. 2004 early May 2005 Lump sum mobe to GOM beginning early May and ending early
Oct., including prep; followed by LOI with Amerada Hess for
one-year term plus mobe in low 200's in GOM beginning early
Oct. 2005 and ending early Oct. 2006. Available; actively
marketing.
- ----------------------------------------------------------------------------------------------------------------------
Ocean Rover late Jan. 2005 early June 2005 LOI with Murphy for 950 day extension at average dayrate in
mid 170's beginning early June 2005 and ending early Jan.
2008. Available; actively marketing.
</Table>
4
DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF MAY 9, 2005
<Table>
<Caption>
RIG NAME WD DESIGN LOCATION STATUS* OPERATOR CURRENT TERM DAYRATE (000S)
- --------------------------------------------------------------------------------------------------------------------------------
BRAZIL
- --------------------------------------------------------------------------------------------------------------------------------
Ocean Yatzy 3,300' DP DYVI Super Yatzy Brazil Contracted Petrobras 700 day extension mid 70's
- --------------------------------------------------------------------------------------------------------------------------------
Ocean Winner 3,500' Aker H-3 Brazil Contracted Petrobras 700 day extension mid 50's
- --------------------------------------------------------------------------------------------------------------------------------
Ocean Alliance 5,000' Alliance Class Brazil Contracted Petrobras one year extension high 90's
- --------------------------------------------------------------------------------------------------------------------------------
INTERNATIONAL DRILLSHIPS(1)
- --------------------------------------------------------------------------------------------------------------------------------
Ocean Clipper 7,500' DP Fluor/Mitsubishi Brazil Contracted Petrobras 700 day extension low 100's
- --------------------------------------------------------------------------------------------------------------------------------
INTERNATIONAL JACKUPS(2)
- --------------------------------------------------------------------------------------------------------------------------------
Ocean Sovereign 250' Independent Leg Indonesia Contracted Santos eight wells upper 60's
Cantilever
- --------------------------------------------------------------------------------------------------------------------------------
Ocean Heritage 300' Independent Leg Shipyard Contracted DODI -- --
Cantilever
- --------------------------------------------------------------------------------------------------------------------------------
UPGRADE(1)
- --------------------------------------------------------------------------------------------------------------------------------
Ocean Endeavor 2,000' Victory Class Under tow Upgrading DODI -- --
- --------------------------------------------------------------------------------------------------------------------------------
COLD STACKED(1)
- --------------------------------------------------------------------------------------------------------------------------------
Ocean New Era 1,500' Korkut GOM Cold Stacked DODI -- --
- --------------------------------------------------------------------------------------------------------------------------------
ASSET HELD FOR SALE(1)
- --------------------------------------------------------------------------------------------------------------------------------
Ocean Liberator 600' Aker H-3 S. Africa Cold Stacked DODI -- --
- --------------------------------------------------------------------------------------------------------------------------------
PURCHASE PENDING -- RESERVED FOR UPGRADE(1)**
- --------------------------------------------------------------------------------------------------------------------------------
Garden Banks 2,200' Victory Class GOM Out of Service -- --
</Table>
<Table>
<Caption>
EST. END
RIG NAME START DATE DATE FUTURE CONTRACTS AND OTHER INFORMATION
- -----------------------------------------------------------------------------------------------------------------------
BRAZIL
- -----------------------------------------------------------------------------------------------------------------------
Ocean Yatzy early Nov. 2003 mid Oct. 2005 Available; actively marketing.
- -----------------------------------------------------------------------------------------------------------------------
Ocean Winner early April 2004 mid Mar. 2006 Available; actively marketing.
- -----------------------------------------------------------------------------------------------------------------------
Ocean Alliance early Sept. 2004 early Sept. 2005 Available; actively marketing.
- -----------------------------------------------------------------------------------------------------------------------
INTERNATIONAL DRILLSHIPS (1)
- -----------------------------------------------------------------------------------------------------------------------
Ocean Clipper early Jan. 2003 early Mar. 2006 Available; actively marketing.
- -----------------------------------------------------------------------------------------------------------------------
INTERNATIONAL JACKUPS (2)
- -----------------------------------------------------------------------------------------------------------------------
Ocean Sovereign early May 2005 late Nov. 2005 Available; actively marketing.
- -----------------------------------------------------------------------------------------------------------------------
Ocean Heritage -- -- Shipyard late April until mid May; followed by two wells
plus option with Conoco/Phillips in Qatar in mid 70's
beginning mid May 2005 and ending early Feb. 2006.
Available; actively marketing.
- -----------------------------------------------------------------------------------------------------------------------
UPGRADE (1)
- -----------------------------------------------------------------------------------------------------------------------
Ocean Endeavor -- -- Mobing to Singapore shipyard for upgrade to 10,000 ft.
capable 5th Generation rig. Estimated completion early 2007.
Available; actively marketing.
- -----------------------------------------------------------------------------------------------------------------------
COLD STACKED (1)
- -----------------------------------------------------------------------------------------------------------------------
Ocean New Era -- -- Cold stacked Dec. '02.
- -----------------------------------------------------------------------------------------------------------------------
ASSET HELD FOR SALE (1)
- -----------------------------------------------------------------------------------------------------------------------
Ocean Liberator -- -- Cold stacked Nov. '02.
- -----------------------------------------------------------------------------------------------------------------------
PURCHASE PENDING -- RESERVED FOR UPGRADE (1)**
- -----------------------------------------------------------------------------------------------------------------------
Garden Banks -- -- Currently retired from active service as drilling and
production platform.
</Table>
NOTES:
* GENERALLY, RIG UTILIZATION RATES APPROACH 95-98% DURING CONTRACTED PERIODS;
HOWEVER, UTILIZATION RATES CAN BE ADVERSELY IMPACTED BY ADDITIONAL DOWNTIME DUE
TO UNSCHEDULED REPAIRS AND MAINTENANCE, WEATHER CONDITIONS AND OTHER FACTORS.
**DIAMOND OFFSHORE SERVICES COMPANY HAS ENTERED INTO A DEFINITIVE AGREEMENT TO
PURCHASE THE GARDEN BANKS, SUBJECT TO CERTAIN CONDITIONS, WHICH IS EXPECTED TO
BE CONSUMMATED IN SEPTEMBER 2005. DIAMOND OFFSHORE DOES NOT CURRENTLY OWN THE
RIG.
GOM = Gulf of Mexico