How does a hovercraft work?

               The hovercraft is an ingenious machine that rides on a cushion of air. It looks like a flat-bottomed ship, and is usually powered with huge propellers like those of an aeroplane. Engines draw in large amounts of air, which is pumped out under the hovercraft and kept in by flexible rubber skirts. The craft rises up, supported on the column of air, and is then able to travel quickly over the water or over land. There is little friction because the bottom of the hovercraft does not actually touch the water.

               Hovercrafts have a number of uses, but have never replaced ordinary ships because they are expensive to run, very noisy and are unable to operate in stormy seas.

Picture credit: google