A further roughly 13,000 amphibious jeeps were built by Ford under the name GPA (nicknamed "Seep" for "Sea Jeep"). Inspired by the larger DUKW, the vehicle was produced too quickly and proved to be too heavy, too unwieldy, and with insufficient freeboard. In spite of participating with some success in the Sicily landings in July 1943, many were passed on under the Lend-Lease program; some 3,500 to the U.S.S.R. alone. The Soviets were sufficiently pleased with its ability to cross the many rivers and swamps in their territories, to develop their own version of it after the war, the GAZ-46 MAV.