Owned by the US Marine Corps, the Amphibious Assault Vehicle (AAV) is a ship-to-shore troop transporter and fully armed combat vehicle. The AAV weighs close to 30 tons and can carry 21 combat-ready Marines and a crew of three. The amphibious tanks launch from the sea-level well decks of assault ships and roar through the water at ten knots (18.5 kilometres/11.5 miles per hour) powered by two rear water jets. The jets are mixed-flow, reversible pumps that propel 52,990 litres (14,000 gallons) of water per minute. In addition to the jets, the AAV gets some propulsion from its spinning tracks. The AAV rides low in the water and can fire its .50-calibre machine gun and 40-millimetre (1.6-inch) grenade launcher on both land or sea. It makes a seamless transition from ocean to shore and carries enough fuel to haul 4,535 kilograms (10,000 pounds) of cargo as far as 480 kilometres (300 miles) inland.