A commercial hovercraft is a specialized form of amphibious vehicle that operates on a cushion of air which is created through the downward thrust of its engines. This cushion of air allows the hovercraft to travel over flat surfaces such as land, water and mud. Large commercial hovercrafts, known as HOVs, are often used to transport passengers and freight across rugged terrain like marshes, shallow rivers and lagoons, as well as through inland waterways where traditional boats and ships cannot be used.