Subscribe to Naked Science - http://goo.gl/wpc2Q1 Every other Wednesday we present a new video, so join us to see the truth laid bare... This machine breaks all the rules, it can penetrate some of the toughest terrains on earth, over land, over water, from the polar ice, to the rapids of the Amazon. This is the ultimate frictionless floating machine, the incredible hovercraft. 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. Hovercraft use blowers to produce a large volume of air below the hull that is slightly above atmospheric pressure. The pressure difference between the higher pressure air below the hull and lower pressure ambient air above it produces lift, which causes the hull to float above the running surface. For stability reasons, the air is typically blown through slots or holes around the outside of a disk or oval shaped platform, giving most hovercraft a characteristic rounded-rectangle shape. Typically this cushion is contained within a flexible "skirt", which allows the vehicle to travel over small obstructions without damage. The first practical design for hovercraft derived from a British invention in the 1950s to 1960s. They are now used throughout the world as specialised transports in disaster relief, coastguard, military and survey applications as well as for sport or passenger service. Very large versions have been used to transport hundreds of people and vehicles across the English Channel whilst others have military applications used to transport tanks, soldiers and large equipment in hostile environments and terrain.