Abstract: A powered watercraft (1) for support and surface-transport of a user lying prone. The watercraft (1) has a hull (3) formed by a moulded shell (20) of expanded plastics strengthened by a metal framework (27) which extends lengthwise of the hull. The framework (27) has two arms (29) that extend laterally to hand-grips (10) on either side of the hull (3). The watercraft (1) is steered by shifting of the user's weight to one side or the other while gripping the hand-grips. The craft (1) is powered by an electric motor (5) coupled to a rearwardly-facing shrouded-propeller (4) on an underside (6) of the shell (20). Electronic motor controls are housed in a watertight metal box (31) incorporated into the framework (27), and motor-speed is regulated via lever mechanisms (9) at the hand-grips. Heat is dissipated via a heat-sink plate (42) exposed directly to the flow through the duct (7).