An underwater propulsion system is disclosed comprising a foot board with one or more battery-powered propulsion units. A throttle control system may be enabled in the foot board such that a movement of the user's foot controls the throttle. Flattened Lithium batteries allow thin lightweight construction of the foot board. Use of trolling motors as propulsion units provides thrust advantages over pre-existing underwater scooters.

A self-propelled personal flotation apparatus provides a motorized flotation board which includes internal water propulsion equipment and associated push-button controls. In use, a user straps the apparatus onto their chest area, enters a body of water such as a lake, a pond, or a pool, and is propelled across the water surface.

A self-propelled personal flotation apparatus provides a motorized flotation board which includes internal water propulsion equipment and associated push-button controls. In use, a user straps the apparatus onto their chest area, enters a body of water such as a lake, a pond, or a pool, and is propelled across the water surface.

In an oscillating fin propulsion apparatus operatively connected to a scuba diver moving on or through a body of water, a propulsive force may be produced by a pair of fins adapted to sweep back and forth in a generally transverse direction relative to the longitudinal axis of the scuba diver's body. The fins may be mounted on opposite sides of a frame detachably secured to a scuba tank. The fins may be rotatable in an oscillatory motion about respective axes coplanar to the center longitudinal axis of the frame. Drive members operable by the scuba diver may be operatively connected to the fins. The oscillating fins may provide a propulsive force to propel the scuba diver longitudinally forward during both oscillating directions of the fins as they sweep back and forth.

In an oscillating fin propulsion apparatus operatively connected to a scuba diver moving on or through a body of water, a propulsive force may be produced by a pair of fins adapted to sweep back and forth in a generally transverse direction relative to the longitudinal axis of the scuba diver's body. The fins may be mounted on opposite sides of a frame detachably secured to a scuba tank. The fins may be rotatable in an oscillatory motion about respective axes coplanar to the center longitudinal axis of the frame. Drive members operable by the scuba diver may be operatively connected to the fins. The oscillating fins may provide a propulsive force to propel the scuba diver longitudinally forward during both oscillating directions of the fins as they sweep back and forth.

A waterjet propulsion apparatus comprising a motor, an impeller driven by the motor via a drive shaft, and a power source. A fluid flow-path is formed through the apparatus, the flow-path extending from at least one fluid inlet, through two propulsion passages, each propulsion passage extending from a propulsion inlet to an outlet located at a rear end of the apparatus. The impeller is located within the flow-path, after the at least one fluid inlet, and before the propulsion inlet of the each of the propulsion passages. The motor is located outside of the flow-path, between the two propulsion passages, and behind the impeller. The apparatus is advantageous in that it provides a compact and lightweight construction that can, for example, be used as part of a personal marine propulsion device that can be used by an individual.

A waterjet propulsion apparatus comprising a motor, an impeller driven by the motor via a drive shaft, and a power source. A fluid flow-path is formed through the apparatus, the flow-path extending from at least one fluid inlet, through two propulsion passages, each propulsion passage extending from a propulsion inlet to an outlet located at a rear end of the apparatus. The impeller is located within the flow-path, after the at least one fluid inlet, and before the propulsion inlet of the each of the propulsion passages. The motor is located outside of the flow-path, between the two propulsion passages, and behind the impeller. The apparatus is advantageous in that it provides a compact and lightweight construction that can, for example, be used as part of a personal marine propulsion device that can be used by an individual.

An underwater propulsion device is disclosed comprising two sleeves for fitting around each of a user's lower legs, with each sleeve mounting a propulsion unit, and the sleeves being connectable by a bar between them during underwater operation of the device by the user.

An underwater propulsion device is disclosed comprising two sleeves for fitting around each of a user's lower legs, with each sleeve mounting a propulsion unit, and the sleeves being connectable by a bar between them during underwater operation of the device by the user.

An underwater swimming aid includes a power device and a camera instrument fixing device, and the power device includes a propeller for providing power to drive the underwater swimming aid to advance and a connecting plate fixed to the propeller; and the camera instrument fixing device includes a mounting bracket and a fixing bracket, the mounting bracket is fixed to the connecting plate and is fixedly connected to the fixing bracket, and the fixing bracket is used for fixing a camera instrument. According to the underwater swimming aid, the camera instrument fixing device is fixed to an existing underwater swimming aid, and the camera instrument is mounted on the camera instrument fixing device, so that users can photograph underwater scenes while enjoying funs brought by the swimming aid.