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.

Because a hovercraft is a vehicle that glides over a smooth surface by riding on a cushion of air, it is also called an air-cushion vehicle, or ACV there is less friction between the hovercraft and the water and in the case of boats their bottoms are under water and there is viscous drag. In magnetic trains the train is slightly above the ground so there is only air resistance acting on the train whereas in trains the wheels touch the rails which create friction