A personal water craft (PWC), also called water scooter, is a recreational watercraft that the rider sits or stands on, rather than inside of, as in a boat. They have an inboard(船内に搭載された)engine driving a pump jet that has a screw-shaped impeller(羽根車)to create thrust(推進)for propulsion(推進力)and steering. Most are designed for two or three people, though four-passenger models exist.