Abstract: A small submersible propulsion unit for use in water sports such as snorkeling or skindiving. The propulsion unit includes an internal combustion engine and a propulsion device driven by the engine. Air is supplied to the engine for its combustion through an air box that is formed above the engine and which draws air through a snorkel device having a float operated valve for preventing the ingestion of water if the propulsion unit becomes submerged to a large extent. In addition, certain accessories for the engine are disposed in the air box and are accessible through an access opening in the air box for servicing.

Abstract: A remote control system for controlling the actuation of control levers through an actuator unit from a remote location by a moveable operator. The system includes a control position detector for detecting the position of the operator which is directly connected to the operator to reduce the manual effort required for actuation of the control levers and to improve the responsiveness of the system.

Abstract: A navigation stabilizing system for a water jet propulsion vessel which includes a water jet unit that has an impeller housing in which an impeller is positioned for drawing water through a water inlet and discharging it through a discharge port in the housing for propulsion of the water vessel. The vessel further includes a rudder which is disposed behind the water inlet port and set off center of the water inlet port and off center of the center line of the hull of the vessel.

Abstract: A remote control system for controlling the actuation of a pair of control levers through a control unit and an actuator unit from a remote location by a moveable operator. The operator is attached to a drive plate for rotation when the operator is moved. A contact element is associated with the drive plate and is adapted to make contact with one or the other of a pair of friction plates after the operator is rotated through a predetermined angle from its upright position so that the frictional force between the contact element and the friction plate increases as the angle of rotation of the operator increases from the predetermined angle.