A hovercraft, also known as an air-cushion vehicle or ACV, is a craft capable of travelling over land, water, mud or ice and other surfaces. Hovercraft are hybrid vessels operated by a pilot as an aircraft rather than a captain as a marine vessel. Although now a generic term for the type of craft, the name Hovercraft itself was a trademark owned by Saunders-Roe (later British Hovercraft Corporation (BHC), then Westland), hence other manufacturers' use of alternative names to describe the vehicles.