AAVP-7A1 Tracked Amphibious Landing Vehicle 

The AAV-P7/A1 is the current amphibious troop transport of the United States Marine Corps. It is used by U.S. Marine Corps Amphibious Assault Battalions to land the surface assault elements of the landing force and their equipment in a single lift from assault shipping during amphibious operations to inland objectives and to conduct mechanized operations and related combat support in subsequent mechanized operations ashore. It is also operated by other forces. Marines call them "amtracs", a shortening of their original designation, "amphibious tractor".