A water-skimming vessel, popularly known as a hydro-plane, can be referred to by a number of synonyms depending on its size and certain characteristics. Some alternate terms for hydro-plane include skim-board, hovercraft, air-boat, or jet-ski. Skim-board refers to a smaller type of hydro-plane that is propelled by the rider's momentum. Hovercraft is a larger version used for transportation or military purposes, powered by engines and propelled by air. Air-boats and jet-skis are two other types of motorized hydro-planes, with different designs and capabilities. Synonyms can offer varied descriptions and clarify specific aspects depending on the type of vessel being referenced.