Amphibious vehicle

An amphibious vehicle (or simply amphibian), is a vehicle that is a means of transport, viable on land as well as on (or under) water. Amphibious vehicles include amphibious bicycles, ATVs, cars, buses, trucks, military vehicles, and hovercraft.

Classic landing craft are not amphibious vehicles as they do not offer any real land transportation at all, although they are part of amphibious assault. Ground effect vehicles, such as Ekranoplans, will likely crash on any but the flattest of landmasses so are also not considered to be amphibious vehicles.

General technical notes

Apart from the distinction in sizes mentioned above, two main categories of amphibious vehicle are immediately apparent: those that travel on an air-cushion (Hovercraft) and those that do not. Amongst the latter, many designs were prompted by the desire to expand the off-road capabilities of land-vehicles to an "all-terrain" ability, in some cases not only focused on creating a transport that will work on land and water, but also on intermediates like ice, snow, mud, marsh, swamp etc. This explains why many designs use tracks in addition to or instead of wheels, and in some cases even resort to articulated body configurations or other unconventional designs such as screw-propelled vehicles which use auger-like barrels which propel a vehicle through muddy terrain with a twisting motion.