A marine drive unit for a boat includes a cooling compartment arranged in a drive unit body. The cooling compartment forms part of a closed cooling circuit, where the cooling circuit is arranged to cool propulsion components of the boat, where the cooling compartment comprises an inlet opening, an inlet channel, a lower end, an outlet channel and an outlet opening, where the inlet channel forms a first flow path for a cooling fluid from the inlet opening to the lower end of the cooling compartment. The outlet channel forms a second flow path for the cooling fluid from the lower end of the cooling compartment to the outlet opening, thereby allowing heat from the cooling fluid to dissipate through the outer wall of the drive unit.

This automatic ship handling system includes a ship and a communication device, the ship includes an actuator that has a function of generating a propulsion force for the ship and a function of generating a turning moment on the ship, an operation unit that receives an input operation for activating the actuator, and a ship control device that activates the actuator on the basis of at least the input operation received by the operation unit, the ship control device has a manual ship handling mode in which the actuator is activated on the basis of the input operation received by the operation unit, and an automatic ship handling mode in which the actuator is activated without a need for the operation unit to receive the input operation, and in the automatic ship handling mode, the ship control device controls a speed of the ship on the basis of a relative distance between the ship and the communication device.

This automatic ship handling system includes a ship and a communication device, the ship includes an actuator that has a function of generating a propulsion force for the ship and a function of generating a turning moment on the ship, an operation unit that receives an input operation for activating the actuator, and a ship control device that activates the actuator on the basis of at least the input operation received by the operation unit, the ship control device has a manual ship handling mode in which the actuator is activated on the basis of the input operation received by the operation unit, and an automatic ship handling mode in which the actuator is activated without a need for the operation unit to receive the input operation, and in the automatic ship handling mode, the ship control device controls a speed of the ship on the basis of a relative distance between the ship and the communication device.

A method for controlling a marine propulsion device having an engine rotatably engaged with a transmission via a clutch, and rotatably engaged with a charging device for charging a battery. The method includes measuring a voltage of the battery and comparing the voltage to a minimum threshold. The method further includes increasing a speed of the engine when the voltage is below the minimum threshold, and also increasing a slip of the clutch when the speed of the engine is increased in response to the voltage being below the minimum threshold.

A method for controlling a marine propulsion device having an engine rotatably engaged with a transmission via a clutch, and rotatably engaged with a charging device for charging a battery. The method includes measuring a voltage of the battery and comparing the voltage to a minimum threshold. The method further includes increasing a speed of the engine when the voltage is below the minimum threshold, and also increasing a slip of the clutch when the speed of the engine is increased in response to the voltage being below the minimum threshold.

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 ship propulsion device includes three or more propulsion units, a malfunction detection unit, and a control unit. The control unit is configured to control the three or more propulsion units. The three or more propulsion units are disposed with left-right symmetry. Based on a malfunction detected in any one of the three or more propulsion units by the malfunction detection unit while the three or more propulsion units are operating, the control unit is configured to stop the propulsion unit in which the malfunction is detected, and, on a left side and a right side of a hull, stop at least one propulsion unit of the three or more propulsion units disposed on the side opposite from the side on which the propulsion unit in which the malfunction is detected is disposed.

A control device of a marine vessel includes a wireless master unit to wirelessly communicate with a wireless slave unit possessed or worn by a vessel operator, and a processor configured or programmed to function as a detecting unit to detect that an engaging portion of a lanyard connectable to a connecting portion provided on a hull of the marine vessel is detached from the connecting portion, an obtaining unit to obtain a physical quantity that indicates at least one of a rotation speed of a drive source that propels the hull and a vessel speed, a judging unit to judge a state of wireless communication between the wireless master unit and the wireless slave unit, and a control unit to control the drive source based on a detection result obtained by the detecting unit, the physical quantity obtained by the obtaining unit, and a judgment result obtained by the judging unit.

A control device of a marine vessel includes a wireless master unit to wirelessly communicate with a wireless slave unit possessed or worn by a vessel operator, and a processor configured or programmed to function as a detecting unit to detect that an engaging portion of a lanyard connectable to a connecting portion provided on a hull of the marine vessel is detached from the connecting portion, an obtaining unit to obtain a physical quantity that indicates at least one of a rotation speed of a drive source that propels the hull and a vessel speed, a judging unit to judge a state of wireless communication between the wireless master unit and the wireless slave unit, and a control unit to control the drive source based on a detection result obtained by the detecting unit, the physical quantity obtained by the obtaining unit, and a judgment result obtained by the judging unit.

A method for using a system including a plurality of first fields and a plurality of second fields fixed to a first device and presenting a first physical characteristic and a second physical characteristic, respectively, the first and second fields being arranged in an alternating manner. First and second sensors are fixed to the second device and arranged to move along the array of fields when the second device moves in relation to the first device. The method includes detecting, by the first sensor and during a movement of the second device in relation to the first device, a transition from the first to the second physical characteristic, or vice versa, simultaneously detecting, by the second sensor, the first or the second physical characteristic, and determining, based on the detected transition and physical characteristic, the direction of movement of the second device in relation to the first device.