A propulsion device includes a platform with a pair of elbowed tubular thrust nozzles respectively located on opposite sides of the platform. An input end of each nozzle is mounted to the platform and rotatable about a transverse axis that is normal to a longitudinal axis of the platform, and is connected to a source of pressurized fluid. A pair of actuators are respectively connected to the tubular nozzles to rotate the nozzles around the transverse axis and thereby change the orientation of output ends of the nozzles relative to the platform. A processor controls the position of the platform by activating the actuators to rotate the nozzles, and thereby change the direction of thrust emitted by the pressurized fluid at the output ends of the nozzles.

A propulsion device includes a platform with a pair of elbowed tubular thrust nozzles respectively located on opposite sides of the platform. An input end of each nozzle is mounted to the platform and rotatable about a transverse axis that is normal to a longitudinal axis of the platform, and is connected to a source of pressurized fluid. A pair of actuators are respectively connected to the tubular nozzles to rotate the nozzles around the transverse axis and thereby change the orientation of output ends of the nozzles relative to the platform. A processor controls the position of the platform by activating the actuators to rotate the nozzles, and thereby change the direction of thrust emitted by the pressurized fluid at the output ends of the nozzles.

A motorized, steerable, electrically-operated personal watercraft that includes a hull with a bow, stern, top deck surface, underside surface, and a support and steering console. The deck is configured to allow a user to lie prone on the deck with the user's chest located on or proximate the console. There are left and right steering control devices located at the left and right of the console, respectively. The steering control devices are configured to be manipulated by the left and right hands of the user. Motive power and steering are both provided through an electrically-powered water jet, which may be but need not be located at the stern. The water jet is mounted to a fixture that is configured such that the outlet nozzle of the jet can be turned left and right, in order to steer the craft to the left and right. Jet nozzle steering is accomplished by manipulation of the left and right steering controls. User-operable kill switches also located at the left and right of the console must be operated in order to operate the jet.

A low emission submersible engine is part of a multipurpose aquatic device, such as an aquatic craft or an electrical generator. A propulsion system having a propeller is coupled to the submersible engine to produce a swimmer propulsion machine and a generator is attached to the engine to produce an electrical generator. The submersible engine receives air from a snorkel that extends up above a water line. The aquatic device has a fuel reservoir which may receive liquid fuel or may receive a fuel cylinder. Floatation chambers keep the aquatic device afloat with the engine submerged. The exhaust assembly and exhaust ports from the engine may also be submerged and the exhaust ports may provide additional thrust. A propulsion system housing integrates the drive shaft and propeller, clutch coupler, exhaust conduits and water flow conduits and is detachably attachable to the engine.

A low emission submersible engine is part of a multipurpose aquatic device, such as an aquatic craft or an electrical generator. A propulsion system having a propeller is coupled to the submersible engine to produce a swimmer propulsion machine and a generator is attached to the engine to produce an electrical generator. The submersible engine receives air from a snorkel that extends up above a water line. The aquatic device has a fuel reservoir which may receive liquid fuel or may receive a fuel cylinder. Floatation chambers keep the aquatic device afloat with the engine submerged. The exhaust assembly and exhaust ports from the engine may also be submerged and the exhaust ports may provide additional thrust. A propulsion system housing integrates the drive shaft and propeller, clutch coupler, exhaust conduits and water flow conduits and is detachably attachable to the engine.

A handheld propulsion unit for use by a user in and under water is disclosed. The handheld propulsion unit includes a tubular shaped housing assembly having a forward and rearward end. A channel defined by the tubular shaped housing assembly allows a flow of water to move through the tubular shaped housing assembly. At least one frame member connected to the tubular shaped housing attaches an electric motor within the channel such that the electric motor is coaxially aligned with the channel. A propeller coaxially coupled directly to a rotating part of the electric motor eliminates a drive transfer assembly or a drive transfer housing from spanning the channel. Hand grips on the tubular shaped housing assembly are configured for being held by the user and allowing the user to maneuver a thrust provided by the flow of water through the channel when the propeller is operating.

A handheld propulsion unit for use by a user in and under water is disclosed. The handheld propulsion unit includes a tubular shaped housing assembly having a forward and rearward end. A channel defined by the tubular shaped housing assembly allows a flow of water to move through the tubular shaped housing assembly. At least one frame member connected to the tubular shaped housing attaches an electric motor within the channel such that the electric motor is coaxially aligned with the channel. A propeller coaxially coupled directly to a rotating part of the electric motor eliminates a drive transfer assembly or a drive transfer housing from spanning the channel. Hand grips on the tubular shaped housing assembly are configured for being held by the user and allowing the user to maneuver a thrust provided by the flow of water through the channel when the propeller is operating.

A system, methods and apparatus for powered monofin that propels a swimmer through water uses one of two modes of power: 1. An electric-assist mode, in which the propulsor responds to a swimmer's kick by multiplying the work of the swimmer; 2. Inverse mode, in which the propulsor deactivates when the swimmer is working. In this mode, propulsion is inversely related to the work of the swimmer. As the swimmer does more work, power from the monofin is reduced, to a predetermined, average level of propulsion. As the swimmer does less work propulsion increases to the predetermined level.

A system, methods and apparatus for powered monofin that propels a swimmer through water uses one of two modes of power: 1. An electric-assist mode, in which the propulsor responds to a swimmer's kick by multiplying the work of the swimmer; 2. Inverse mode, in which the propulsor deactivates when the swimmer is working. In this mode, propulsion is inversely related to the work of the swimmer. As the swimmer does more work, power from the monofin is reduced, to a predetermined, average level of propulsion. As the swimmer does less work propulsion increases to the predetermined level.

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.