A marine propulsion system, comprising a drive shaft secured to a propeller to rotationally drive the propeller; a motor selectively coupled to the drive shaft to rotate the drive shaft; an electrical energy storage unit coupled to the motor to supply an on-board electrical power supply to the motor, the electrical energy storage unit configured to be recharged by an on-shore electrical power supply; an engine selectively coupled to the drive shaft to rotate the drive shall, the engine not coupled to the electrical energy storage unit for use as a generator to recharge the electrical energy storage unit; and a control system coupled to the motor and to the engine for selecting one of the motor and the engine to rotate the drive shaft. A hybrid marine propulsion method, comprising rotationally driving a drive shaft and propeller using an engine; shifting the engine into neutral; turning on an electric motor by manually activating a motor toggle; disengaging the engine from rotational driving engagement with the drive shaft and engaging the electric motor in rotational driving engagement with the drive shaft; and turning on a fluid sub-system to supply fluid to the drive shaft by manually activating a fluid sub-system toggle.

A linking drive system comprises a first drive shaft of the first drivetrain connected between a first prime mover and a first propulsor. The linking drive system comprises a second drive shaft of the second drivetrain connected between a second prime mover and a second propulsor. The linking drive system further comprises a linking drive clutch, which comprises at least a first clutch part and a second clutch part. The first clutch part and the second clutch part are engageable with each other and can transmit rotation therebetween. At least one flexible drive link is coupled between the linking drive clutch and the first and/or second drive shafts. Rotation from one of the first and second drive shafts is transferred to the other of the first and second drive shafts when the linking drive clutch is engaged thereby linking the first and second drivetrains.

A powertrain for a marine vessel, comprising an internal combustion engine, a transmission, a first drive unit having a first propeller and a second drive unit having a second propeller, a first electric motor and a second electric motor, where the internal combustion engine is drivingly connected to the first drive unit and the second drive unit through the transmission, that the first electric motor is drivingly connected directly to the first drive unit and that the second electric motor is drivingly connected directly to the second drive unit.

A self-propelling watercraft system is provided. The watercraft has a base with a plurality of sidewalls extending from the base to form a cockpit. The base also has a recess, where a pump can detachably connect to the hull within the recess. The pump has an intake valve on a first end and a nozzle on a second end that is opposite the first end. The intake valve can intake water. The nozzle can jettison water received in the pump from the intake valve and agitate water surrounding the nozzle.

A power transmission device for an outboard motor, comprising a drive shaft, an endless loop flexible drive coupling and a propeller shaft, wherein the endless loop flexible drive coupling operatively connects said drive shaft to said propeller shaft for transferring output power from the drive shaft to the propeller shaft. The power transmission device comprises a first drive shaft, a second drive shaft, a first endless loop flexible drive coupling, a second endless loop flexible drive coupling, a first propeller shaft and a second propeller shaft, wherein the first propeller shaft is connected to the first drive shaft through the first endless loop flexible drive coupling to rotate the first propeller shaft in a first direction, and wherein the second propeller shaft is connected to the second drive shaft through the second endless loop flexible drive coupling to rotate the second propeller shaft in a second direction opposite to the first direction.

A fluid machine (1) having an intake part (21), a discharge part (26), and an impeller (24), the impeller (24) being arranged in an enclosure (18), and a transmission (90) arranged in the enclosure (18) and operationally connecting a rim (11) of the impeller (24) with an energy converter (2,2′).

A power transmission device for an outboard motor, comprising a drive shaft, an endless loop flexible drive coupling and a propeller shaft, wherein the endless loop flexible drive coupling operatively connects said drive shaft to said propeller shaft for transferring output power from the drive shaft to the propeller shaft. The power transmission device comprises a first drive shaft, a second drive shaft, a first endless loop flexible drive coupling, a second endless loop flexible drive coupling, a first propeller shaft and a second propeller shaft, wherein the first propeller shaft is connected to the first drive shaft through the first endless loop flexible drive coupling to rotate the first propeller shaft in a first direction, and wherein the second propeller shaft is connected to the second drive shaft through the second endless loop flexible drive coupling to rotate the second propeller shaft in a second direction opposite to the first direction.

A self-propelling watercraft system is provided. The watercraft has a base with a plurality of sidewalls extending from the base to form a cockpit. The base also has a recess, where a pump can detachably connect to the hull within the recess. The pump has an intake valve on a first end and a nozzle on a second end that is opposite the first end. The intake valve can intake water. The nozzle can jettison water received in the pump from the intake valve and agitate water surrounding the nozzle.

A self-propelling watercraft system is provided. The watercraft has a base with a plurality of sidewalls extending from the base to form a cockpit. The base also has a recess, where a pump can detachably connect to the hull within the recess. The pump has an intake valve on a first end and a nozzle on a second end that is opposite the first end. The intake valve can intake water. The nozzle can jettison water received in the pump from the intake valve and agitate water surrounding the nozzle.

Hydraulic pump-accessory assemblies are provided for engines. The assemblies may include: an accessory pulley or gear configured to engage a drive belt or chain of an engine; and a hydraulic pump operatively engaging the pulley or gear to be driven by the engine. Engines are provided that can include: a crankshaft pulley or gear operably engaging a belt or chain to convey power to one or more accessories; an accessory pulley or gear operably engaged by the belt or chain; and a hydraulic pump operatively engaging the accessory pulley or gear to receive power from the belt or chain. Methods for modifying an engine are also provided. The methods can include operatively engaging a hydraulic motor to the pulley or gear of an accessory configured to be operably engaged with a belt or chain of the engine.