A first outboard motor attached to a vessel body receives an electric operating signal and is controlled in accordance with the electric operating signal. A second outboard motor attached to the vessel body receives a mechanical operating amount and is controlled in accordance with the mechanical operating amount. An operating tool controls shifting and a throttle opening degree of each of the first and second outboard motors. The electric operating signal is transmitted through a first transmission path to the first outboard motor based on an operation of the operating tool. The mechanical operating amount is transmitted through a second transmission path to the second outboard motor based on an operation of the operating tool.

This application includes an electric powered surfboard equipped with drive units that emerge out onto the surfboard's bottom surface to power it forward. Once a wave is caught the drive units can retract back up into the surfboard's body as the power is shut off by the surfer. Then instantly, flush fitting glide doors close, allowing the surfboard's bottom to return to a planing surface with no protrusions, except for fins to detract from the surfboard's critical gliding ability when surfing waves. Also, there's a crowned deck shape that allows thin rail sensitivity for turning performance and a motor battery arrangement that provides mass centralization of weight. All this, combined with several wireless control means define this new fine handling motorized surfboard.

A vessel hull for an inboard-powered marine vessel includes a hull body having a hull bottom that includes a contoured pod mounting surface positioned longitudinally between a central keel and a stern of the hull body. The contoured pod mounting surface has a planar mounting face, for mounting a propulsor pod, and a transition face each positioned between peripheral edges of the pod mounting surface. The transition face slopes forwardly and downwardly from the planar mounting face to the central keel and follows a contour defining a sine wave pattern.

A vessel hull for an inboard-powered marine vessel includes a hull body having a hull bottom that includes a contoured pod mounting surface positioned longitudinally between a central keel and a stern of the hull body. The contoured pod mounting surface has a planar mounting face, for mounting a propulsor pod, and a transition face each positioned between peripheral edges of the pod mounting surface. The transition face slopes forwardly and downwardly from the planar mounting face to the central keel and follows a contour defining a sine wave pattern.

An autonomous water vehicle for moving above the water surface, part of the device being under water and part being lifted above the water surface. The water vehicle includes an underwater propulsion module, an upper platform and a vertical support, a power source and an electronic control unit. The propulsion module has a housing in which at least two propeller groups are preferably mounted, including electric motors and water screw propellers with two to five blades, such as the propeller groups are arranged symmetrically with respect to the central vertical axis of the housing and are designed to generate vertical thrust for lifting the upper platform plus maximum payload above the water surface. The rotational axes of the propeller groups are arranged vertically or at an angle to the central vertical axis of the housing.

An autonomous water vehicle for moving above the water surface, part of the device being under water and part being lifted above the water surface. The water vehicle includes an underwater propulsion module, an upper platform and a vertical support, a power source and an electronic control unit. The propulsion module has a housing in which at least two propeller groups are preferably mounted, including electric motors and water screw propellers with two to five blades, such as the propeller groups are arranged symmetrically with respect to the central vertical axis of the housing and are designed to generate vertical thrust for lifting the upper platform plus maximum payload above the water surface. The rotational axes of the propeller groups are arranged vertically or at an angle to the central vertical axis of the housing.

A ship steering device including: an engine; an auto-drive unit that exerts propulsive power on a ship hull by power from the engine; detection means for detecting a current position and an orientation of the ship hull; a ship steering control device that controls an output of the engine and propulsive power of the auto-drive unit; and a calibration switch that starts calibration of a ship. When the ship steering control device detects that the calibration switch is turned on, the ship steering control device controls the engine and the auto-drive unit to cause the ship hull to move in a predetermined direction or to turn, and if a difference between, for instance, a traveling amount and speed in the predetermined direction and an intended traveling amount and speed exceeds a predetermined value, the ship steering control device corrects control values of the engine and the auto-drive unit.

A first outboard motor attached to a vessel body receives an electric operating signal and is controlled in accordance with the electric operating signal. A second outboard motor attached to the vessel body receives a mechanical operating amount and is controlled in accordance with the mechanical operating amount. An operating tool controls shifting and a throttle opening degree of each of the first and second outboard motors. The electric operating signal is transmitted through a first transmission path to the first outboard motor based on an operation of the operating tool. The mechanical operating amount is transmitted through a second transmission path to the second outboard motor based on an operation of the operating tool.

Disclosed is a method of decreasing pressure fluctuation induced on a surface of a hull due to propeller cavitation by adjusting a relative rotation angle of propellers of a twin-propeller ship.

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.