History
UK
Name	HMS Challenger
Builder	Scotts Shipbuilding and Engineering Company, Greenock[1]
Launched	19 May 1981[1]
Commissioned	1984
Decommissioned	1990
Fate	Sold, 1993
History
Namibia
Name	MV Ya Toivo
Namesake	Andimba Toivo ya Toivo
Operator	list error: <br /> list (help) NAMCO (2000-2003) De Beers (2003-)
Acquired	2000
In service	December 2000
Status	in active service, as of 2010[update]
General characteristics (as built)
Type	Seabed operations vessel[1]
Displacement	list error: <br /> list (help) 6,500 t (6,397 long tons) standard 7,185 t (7,072 long tons) full[1]
Length	134.1 m (440 ft 0 in) o/a[1]
Beam	18 m (59 ft 1 in)[1]
Draught	5 m (16 ft 5 in)[1]
Propulsion	list error: <br /> list (help) Diesel-electric 5 × 6,200 shp (4,623 kW) RKC Ruston 16-cylinder diesel engines, coupled to 3.3 kW alternators driving electric motors (main propulsion) 2 × 6RKC diesel engines (auxiliary power) 2 × Voith-Schneider propellers aft 3 × bow thrusters[1][2]
Aviation facilities	Helicopter deck

HMS Challenger was a unique vessel in Royal Navy service — she was purpose built to support deep sea operations and saturation diving. Built by Scotts at Greenock, the ship was launched on 19 May 1981, but not commissioned until 1984, during a time when the Royal Navy was cutting back on expenditure, with the consequence that the Challenger was seen as an extravagance that the Admiralty could not afford. As a consequence, after only a few years service, in 1990 the ship was laid up and offered for sale.

In 1993 the ship was purchased by a company called Subsea Offshore, to be converted for work decontaminating hazardous waste dumped in the Baltic Sea and North Atlantic.

The vessel was later bought by the Namibian Minerals Corporation (NAMCO), and fitted with equipment to recover diamonds from the sea floor.^[3] The ship was converted at the Nauta Shipyard in Gdynia, Poland,^[4] and made its first diamond recoveries in December 2000.^[3] The ship was bought by De Beers in April 2003 for US$20 million.^[5]