The Army hovercraft, called Air Cushion Vehicles, had more extensive modifications. They had heavier armor and reinforced, load-bearing decks. Army ACVs carried of armor—roughly equal to that of an M113 armored personnel carrier. The armor was thickest around the engine, transmission, and fuel tanks, providing protection from .50 caliber rounds fired at , while the armor around the crew compartment could only block .30 caliber rounds fired at . To save weight, many crews removed the armor around the crew compartment, and an Army evaluation recommended that it be removed altogether because of it "did not provide any protection to the crew," especially against heavier weapons such as recoilless rifles, artillery, and RPGs.