Diamond Offshore Drilling (DODRW) 8-K Regulation FD Disclosure

Exhibit 99.1

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

RECENT COMMITMENTS — (See Body of Report For Contract Details/Date Changes and Other Information)

Rig Name	WD		Location	Status	Operator	Current Term	Dayrate ($000s)		Start Date	Est. End Date
Domestic Deepwater Semisubmersibles (8)
Ocean Quest		3,500’	GOM	Current Contract	Noble	two-year term + unpricedoption	upper 350’s		mid June 2007	midJanuary2009
			GOM/Brazil	Prep, mobe & acceptance test for ENI Brasil/OGX	ENI/OGX			0	midJanuary2009	mid April2009
			Brazil	Future Contract	ENI Brasil	150 day assignment from Noble	mid 380’s		mid April 2009	mid Sept. 2009
			Brazil	Future Contract	OGX	two-year term + unpricedoption	low 420’s		mid Sept. 2009	mid Sept. 2011
Ocean Star		5,500’	GOM	Current Contract	Anadarko	term extension	upper 410’s		early Nov. 2007	late Dec. 2008
			GOM	Future Contract (swap from oldVictory/ Voyager contract in low 300’s)	Newfield	one well	low 300’s		late Dec. 2008	early March2009
			GOM	Future Contract (swap fromVictory contract)	Newfield	one well extension	low 500’s		early March2009	midApril 2009
Ocean America		5,500’	GOM	Current Contract	Mariner	term	mid 460’s		late Oct. 2008	mid July 2009
			GOM	Special Survey & Maintenance	DODI			0	early Jan. 2009	mid April 2009
			GOM	Future Contract	Mariner	1-year term; convertible to 6-month term (ending Jan. 2010) in low 550’s w/notice by 1-Feb. 09	low 530’s		mid July 2009	mid July 2010
Ocean Valiant		5,500’	GOM	Current Contract	Anadarko	one-year term extension	upper 420’s		mid Dec. 2008	late July 2009
			Mobe	Lump sum mobe	DODI				late July 2009	late Sept. 2009
			Angola	Future Contract	Total	two-year term + priced options	low 620’s		late Sept. 2009	late Sept. 2011
Ocean Victory		5,500’	GOM	Current Contract	Callon	two wells	low 500’s		mid Aug. 2008	Customer now plans 1 well instead of 2; contract resolution pending
			GOM	Future Contract	ATP	one-year term, minimum	low 540’s		mid March 2009	mid March 2010
Ocean Baroness		7,000’	GOM	Current Contract	Hess	term extension +unpricedoption	mid 360’s		late Nov. 2007	mid April 2010
Ocean Confidence		10,000’	GOM	Current Contract	Murphy	four-year term + unpricedoption	low 500’s		late Feb. 2008	late March 2012
Ocean Endeavor		10,000’	GOM	Current Contract	Devon	four-year term + unpriced option	mid 290’s		early July 2007	late June 2011

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

Rig Name	WD		Location	Status	Operator	Current Term	Dayrate ($000s)		Start Date	Est. End Date
Domestic 2nd and 3rd Generation Semisubmersibles (2)
Ocean Ambassador		1,100’	GOM	Special Survey & Maintenance (storm delayed)	DODI			0	early Aug. 2008	late Dec.2008
			GOM	Future Contract	Taylor	seven-month term	mid 280’s		late Dec. 2008	mid May2009
			GOM/Brazil	Prep, mobe & acceptance test for OGX	OGX			0	mid May2009	earlySept. 2009
			Brazil	Future Contract	OGX	three-year term + unpricedoption	low 260’s		earlySept. 2009	earlySept. 2012
Ocean Saratoga		2,200’	GOM	Current Contract	Walter	four wells	mid 280’s		early Dec. 2008	early May2009
			GOM	Future Contract	Taylor	16-month term + option	mid 280’s		early May2009	mid July 2010
Domestic Jack-ups (7)
Ocean Crusader	200’ MC		GOM	Current Contract	Walter	two wells	mid 70’s		mid Oct. 2008	early Feb. 2009
Ocean Drake	200’ MC		GOM	Current Contract	Tarpon	one well	mid 60’s		late Oct. 2008	midDec. 2008
			GOM	Future Contract	Tarpon	two wells	mid 70’s		midDec. 2008	midFeb. 2009
Ocean Champion	250’ MS		GOM	Current Contract	Stone	six months + unpricedoption	low 70’s		late Oct. 2008	late April 2009
Ocean Spartan	300’ IC		GOM	Current Contract	Samson	two-well extension, part 1	low 100’s		early Nov. 2008	mid Dec. 2008
			GOM	Future Contract	Samson	two-well extension, part 2	low 120’s		mid Dec. 2008	midFeb. 2009
Ocean Summit	300’ IC		GOM	Current Contract	Energy Partners	five-wells + unpricedoption	low 100’s		mid Nov. 2008	early Jan. 2009
Ocean Titan	350’ IC		GOM	Current Contract	Apache	third of three wells	low 110’s		mid Nov. 2008	early Jan. 2009
			GOM	Future Contract	Apache	four-month extension + unpricedoption	low 130’s		early Jan. 2009	early March2009
			GOM	Special Survey and Maintenance	DODI			0	early March 2009	mid April 2009
			GOM	Future Contract	Apache	resume four-month extension	low 130’s		mid April 2009	mid June 2009
Ocean Tower	350’ IC		GOM	Hurricane Ike Repairs	DODI				mid Oct. 2008	early Oct. 2009

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

Rig Name	WD		Location	Status	Operator	Current Term	Dayrate ($000s)		Start Date	Est. End Date
International Semisubmersibles (19)
MEXICO
Ocean New Era		1,500’	GOM	Current Contract	PEMEX	2 1/2 year term	mid 260’s		late Oct. 2007	mid Feb. 2010
Ocean Voyager		3,000’	GOM	Current Contract	PEMEX	2 1/2 year term	mid 330’s		early Nov. 2007	late Feb. 2010
NORTH SEA/MEDITERRANEAN
Ocean Nomad		1,200’	North Sea	Current Contract	Talisman	resume two-year term extension	mid 330’s		late Oct. 2008	late Sept. 2010
Ocean Guardian		1,500’	North Sea	Current Contract	Oilexco	remainder two-year term	low 350’s		early Sept. 2008	mid July 2009
			North Sea	Future Contract	Oilexco	two-year term extension	mid 380’s		mid July. 2009	early Sept. 2011
Ocean Princess		1,500’	North Sea	Contract interrupted for Special Survey & Maintenance	DODI			0	late Oct. 2008	late Dec. 2008 resume contract
			North Sea	Current Contract	Talisman	resume two-year term extension	upper 330’s		late Dec. 2008	mid April 2010
Ocean Vanguard		1,500’	North Sea	Current Contract	Statoil	two-year term extension + unpricedoption	mid 400’s		late April 2008	mid April 2010
Ocean Lexington		2,200’	Egypt	Current Contract	BP	36-month term	mid 260’s		late Nov. 2006	mid Aug.2009
			Egypt/Brazil	Prep, mobe & acceptance test for OGX	OGX			0	mid Aug. 2009	late Jan. 2010
			Brazil	Future Contract	OGX	three-year term + unpricedoption	mid 330’s		late Jan. 2010	late Jan. 2013

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

Rig Name	WD		Location	Status	Operator	Current Term	Dayrate ($000s)		Start Date	Est. End Date
AUSTRALASIA
Ocean Bounty		1,500’	Australia	Current Contract	Woodside	continue one-year term	low 350’s		early Sept. 2008	late March 2009
			Australia	Future Contract	Woodside	60 days	mid 380’s		late March 2009	late May 2009
			Australia	Re-engine and upgrade	DODI			0	late May 2009	to be determined followed by two-year term
			Australia	Future Contract	Woodside	two-year term	mid 420’s		to be determined	to be determined
Ocean Patriot		1,500’	Australia	Current Contract	Apache	one-year term	upper 370’s		mid May 2008	late Dec. 2008
			Australia	Future Contract	Apache	two-year term + unpricedoption	between 380-420		late Dec. 2008	late Dec. 2010
Ocean Epoch		1,640’	Australia	Current Contract	Apache	one-year term	mid 350’s		early March 2008	early March 2009
			Australia	Future Contract	BHPB	550-day term + unpricedoptions	low 350’s		early March 2009	early Sept. 2010
Ocean General		2,400’	Vietnam	Current Contract	PVEP	Approx. two-year term + unpricedoptions	low 280’s		mid Oct. 2008	late Oct. 2010
Ocean Rover		7,000’	Malaysia	Current Contract	Murphy	balance previously declared option wells	high 240’s		mid Oct. 2008	late Jan. 2009
			Malaysia	Future Contract	Newfield	one well	low 450’s		late Jan. 2009	mid March 2009
			Malaysia	Future Contract	Murphy	two-year term extension	low 450’s		mid March 2009	mid March 2011

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

Rig Name	WD		Location	Status	Operator	Current Term	Dayrate ($000s)		Start Date	Est. End Date
BRAZIL
Ocean Whittington		1,500’	Brazil	Contract interrupted to resume and complete contract upgrade work	DODI			0	mid Oct. 2008	late Dec. 2008 resume contract
			Brazil	Current Contract	Petrobras	resume five-year term plus potential 15% bonus	mid 220’s		lateDec. 2008	late Aug. 2012
Ocean Concord		2,200’	Brazil	Current Contract	Petrobras	five-year term plus potential 15% bonus	low 230’s		mid Jan. 2008	mid Jan. 2013
Ocean Yorktown		2,850’	Brazil	Current Contract	Petrobras	five-year term plus potential 15% bonus	mid 230’s		mid Aug. 2008	mid Aug. 2013
Ocean Yatzy		3,300’	Brazil	Current Contract	Petrobras	four-year term extension plus potential 17% bonus	mid 110’s		early Oct. 2005	early Oct. 2009
			Brazil	Future Contract	Petrobras	five-year term plus potential 10% bonus	mid 240’s		early Oct. 2009	early Oct. 2014
Ocean Winner		3,500’	Brazil	Current Contract	Petrobras	four-year term extension plus potential 5% bonus	low 110’s		mid March 2006	mid March 2010
			Brazil	Future Contract	Petrobras	five-year term extension plus potential 10% bonus	low 270’s		mid March 2010	mid March 2015
Ocean Worker		3,500’	Brazil	Current	DODI	prep., plus acceptance testing		0	late July 2008	lateJan. 2009
			Brazil	Future Contract	Petrobras	six-year term plus potential 10% bonus	low 270’s		lateJan. 2009	lateJan. 2015
Ocean Alliance		5,000’	Brazil	Current Contract	Petrobras	one-well extension retroactive to late March 2008	mid 520’s		late March 2008	lateJan. 2009 resume contract
			Brazil	Future Contract	Petrobras	four-year extension plus 20% potential bonus	mid 150’s		lateJan. 2009	late Nov. 2009
			Brazil	Future Contract	Petrobras	six-year term extension plus potential 15% bonus	low 340’s		late Nov. 2009	late Nov. 2015
International Drillship (1)
Ocean Clipper		7,000’	Brazil	Current Contract	Petrobras	five-year extension plus potential 5% bonus	low 180’s		mid Dec. 2005	mid Dec. 2010

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

Rig Name	WD	Location	Status	Operator	Current Term	Dayrate ($000s)		Start Date	Est. End Date
International Jack-ups (8)
Ocean Columbia	250’ IC	Mexico	Current Contract	Pemex	1 1/2-year term	mid 120’s		late Jan. 2008	mid June 2009
Ocean Nugget	300’ IC	Mexico	Current Contract	Pemex	term contract	upper 160’s		early Oct. 2006	late March 2009
Ocean King	300’ IC	Croatia	Current Contract	CROSCO	two-year bareboat charter	upper 100’s		mid Nov. 2007	early Nov. 2009
Ocean Sovereign	300’ IC	Indonesia	Current Contract	Kodeco	extension up to survey	upper 130’s		early Aug. 2008	late Dec. 2008
		Singapore	Intermediate Survey & upgrade	DODI			0	late Dec. 2008	early March 2009
		Indonesia	Future Contract	Kodeco	15-month extension + unpricedoption	mid 140’s		early March 2009	late April 2010
Ocean Heritage	300’ IC	Gulf of Suez	Current Contract	IPR	seven-month term	mid 110’s		mid July 2008	early Jan.2009
Ocean Spur	300’ IC	Egypt	Current Contract	WEPCO	one-year term	low 140’s		mid Aug. 2008	late Aug. 2009
Ocean Shield	350’ IC	Malaysia	Current Contract	Newfield	six-month term + two wells	mid 170’s		late May 2008	lateDec. 2008
		Malaysia	Future Contract	Newfield	demobe to Singapore, then mobe to Australia followed by term		0	lateDec. 2008	midJan. 2009
		Australia	Future Contract	ENI	term	mid 260’s		midJan. 2009	early Jan. 2010
Ocean Scepter	350’ IC	Argentina	Current Contract	Enap Sipetrol/YPF	300-day term contract + unpriced option	high 190’s		late Sept. 2008	late July 2009

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

Rig Name	WD		Location	Status	Operator	Current Term	Dayrate ($000s)		Start Date	Est. End Date
Upgrade (1)
Ocean Monarch		10,000	mobe GOM	Current	DODI	mobe to GOM and prep for contract		0	mid Dec. 2008	early March2009
			GOM	Future Contract	Anadarko	four-year term + unpricedoption	high 420’s		early March2009	early March2013

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. An LOI is subject to customary conditions, including the execution of a definitive agreement and as such may not result in a binding contract. Options are un-priced and any extension of contract is subject to mutually agreeable terms & conditions unless otherwise indicated. Mobe revenues (if any) and mobe expenses are deferred, and generally are amortized over the life of the contract. GOM = Gulf of Mexico.

Cost/Revenue Footnote: Contract Drilling Expenses applies to contract drilling expenses ONLY anddoes not include Reimbursable Expenses

On rig utilization, assume 95% for DP units, 96% for conventionally moored rigs, and 98% for jack-ups.

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

EXPECTED DOWNTIME LONGER THAN 14 DAYS (Subject to Change)

Actual Oct. 1 — Nov. 30 Down Days (Total thru Q3 = 1,111)	# Days
Rig	Q4 Act.	EST. Q4 Total	Comments
Shipyard Time
Princess	28	59	5-year survey and maintenance
Ambassador	61	74	5-year survey and maintenance
Valiant	61	82	5-year survey/replace derrick and other maint.
Nomad	36	36	5-year survey and maintenance
Drake	31	31	5-year survey and maintenance
Rover	16	16	5-year survey and maintenance
	233	298
Other Downtime
Worker	61	92	Prep for contract, accpt. test
Tower	61	92	Equipment repair (Hurricane Ike damage)
Whittington	49	77	Complete contract upgrade
Sovereign	0	6	Intermediate survey, install new crane & top drive
Shield	0	6	Mobe to Australia
	171	273
Remaining 2008 Non-New-build/Upgrade	404	571
New-build/Upgrade Downtime	Q4	Total
Monarch	61	92	Commission, mobe to U.S. GOM

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

ESTIMATED 2009 DOWNTIME (PRELIMINARY PENDING FINALIZATION OF 2009 BUDGET)

5-YEAR SURVEYS	DAYS	COMMENTS
America	103
Champion	61
Concord	51
Titan	45
Yatzy	42
INTERMEDIATE SURVEYS
Summit	16
Columbia	15
Nugget	13
Heritage	10
OTHER DOWNTIME
Bounty	???	Approx. 1 year re-engine and water depth upgrade — work start time to be determined, may extend into 2010
Tower	274	Hurricane repair
Lexington	161	Prep, mobe & acceptance test
Quest	135	Prep, mobe & acceptance test
Ambassador	110	Prep, mobe & acceptance test
Monarch	75	Complete mobe to GOM and rig prep.
Valiant	60	Mobe
Sovereign	65	Completion of maintenance and upgrade begun in 2008
Worker	20	Complete Prep for contract, accpt. Test begun in 2008
Confidence	18	Thruster changeout
Shield	19	Complete Mobe to Australia begun in 2008

DIAMOND OFFSHORE DRILLING, INC. RIG STATUS REPORT AS OF
December 15, 2008

Forward-Looking Statements: The rig status report 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. Forward-looking statements include, without limitation, any statement that may project, indicate or imply future results, events, performance or achievements, and may contain or be identified by the words “expect,” “intend,” “plan,” “predict,” “anticipate,” “estimate,” “believe,” “should,” “could,” “may,” “might,” “will,” “will be,” “will continue,” “will likely result,” “project,” “budget,” “forecast,” and similar expressions. Statements by the Company in the rig status report that contain forward-looking statements include, but are not limited to, statements regarding the current term, future dayrates, start and end dates and comments concerning future contracts and availability, letters of intent, utilization, surveys, downtime and other aspects of the Company’s drilling rigs, as well as statements concerning rigs being upgraded or to be upgraded and rigs under construction. Such statements are inherently subject to a variety of assumptions, risks and uncertainties that could cause actual results to differ materially from those anticipated or projected. A discussion of the risk factors that could impact these areas and the Company’s overall business and financial performance can be found in the Company’s reports and other documents filed with the Securities and Exchange Commission. These factors include, among others, general economic and business conditions, operating risks, 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 the rig status report, and the Company undertakes no obligation to publicly update or revise any forward-looking statement.