The HMS Ocean entered service in 1998. The 22,500 ton ship is similar to the 21,300 ton French Mistral Class (which Russia has bought three of) and the 41,000 ton U.S. Wasp class. The HMS Ocean has a crew of 461 (including the air squadron) and normally carries 480 Royal Marine Commandos. As many as 800 marines can be crammed aboard for short voyages. The ship can carry up to 40 vehicles but can only land trucks and jeeps via the four LCVP landing craft. Normally 18 helicopters are carried (12 transports and six lighter scout or attack models). Army helicopters pilots have practiced operation from HMS Ocean and did so for combat missions off Libya last year.