This British hovercraft is held above the water by blown air. Once the craft is hovering over the surface, it moves much more efficiently than a boat plowing through water. The propellers on the rear help to power as well as to steer the hovercraft (Hovercraft, Commercial Hovercraft Entered Service Ships, Passenger Transport Ships, English Ships).
Hovercraft, also called air-cushion vehicles, travel over the surface of, rather than through, the water.
They use large lift fans to push down air, which is trapped inside a heavy rubber skirt. The skirt gives the craft the hover height necessary to clear waves and other obstacles. Without water resistance, these ships can travel at up to 65 knots over the water. If their skirts or lift fans fail, the hovercraft settles onto the surface of the water and floats for the rest of the trip to port (Hovercraft, Commercial Hovercraft Entered Service Ships, Passenger Transport Ships, English Ships).