Development Driller III is a fifth generation, Vanuatu-flagged dynamic positioning semi-submersible ultra-deepwater drilling rig owned by Transocean and operated under lease agreements by various petroleum exploration and production companies worldwide. The vessel is capable of drilling in water depths up to 7,500 feet (2,300 m) with drilling depth of 35,000 feet (11,000 m), upgradeable to 37,500 feet (11,400 m).^[3]

Development Driller III, Q4000, Discoverer Enterprise on the site of the Deepwater Horizon oil spill on 18 May 2010
History
Name	Development Driller III
Owner	Transocean
Operator	Transocean
Port of registry	Vanuatu, Port Vila
Ordered	12 January 2006
Builder	Keppel AmFELS, Singapore
Laid down	25 November 2006
Acquired	22 May 2009
Identification	ABS class no.:09172785 Call sign: YJVD2 DNV ID: 30254 IMO number: 8769121 MMSI number: 576281000
Status	Operational
Notes	[1]
General characteristics
Tonnage	37,981 GT 23,513 DWT
Length	117 m (384 ft)
Beam	78 m (256 ft)
Draught	19 m (62 ft)
Depth	37 m (121 ft)
Deck clearance	77.10 m (253.0 ft)
Propulsion	8 × Caterpillar 3616 diesel engines
Capacity	Diesel oil: 4,546.7 m3 (160,570 cu ft) Freshwater: 2,934.98 m3 (103,648 cu ft) Lube oil: 71.78 m3 (2,535 cu ft) Tank ballast: 21,891.81 m3 (773,102 cu ft) Other: 341.84 m3 (12,072 cu ft)
Crew	200
Notes	[2]

On 2 May 2010, Development Driller III started drilling a relief well on Macondo Prospect to stop massive oil spill caused by the explosion and subsequent loss of the Deepwater Horizon.^[4]