Personal water craft
noun - Personal water craft or PWC, also called water scooter, is a recreational watercraft that the rider rides or stands on, rather than inside of, as in a boat. It is used for safety purposes in many open water swimming events.
These have an inboard engine driving a pump jet that has a screw-shaped impeller to create thrust for propulsion and steering. They are often referred by the trademarked brand names 'Jet Ski', 'WaveRunner', or 'Sea-Doo'. There are a wide variety of "jet boats" many of which exceed 30-40' in length. The Coast Guard defines a personal watercraft, amongst other criteria, as a jet drive boat less than 13' in length, in order to exclude from that definition, more conventional sized jet boats. Most are designed for two or three people, though four-passenger models exist.