A propulsion device for moving a person over a water surface comprises a hull (1) containing propulsion means in the form of a propulsion device (8) and drive means (6, 7) for the propulsion device (8) and also having handles (3) for the person to grip so that a person can be towed in a prone position over a water surface. The propulsion device (8) is contained in a through water channel (11) extending in the fore to aft direction for creating a water flow through the channel (11) whereby to propel the device across a water surface. The channel (11) has a downward direction at its exit end when viewed in the "straight ahead" position of the hull so that steering of the device can be achieved by tilting the device through the handles (3) about a fore to aft axis. The drive means comprises at least one permanent magnet motor (6) energised from a battery pack (9) of secondary cells.
