A boat includes: a hull; a float that supports the hull; a suspension that is disposed between the hull and the float and absorbs vibration transmitted from the float to the hull; a sensor that detects an interval between the hull and the float in a vertical direction; a control unit that generates a control signal in accordance with the interval; a battery that is charged or discharged in accordance with the control signal; and a motor that generates electric power by utilizing relative movement between the hull and the float in the vertical direction, charges the battery with the generated electric power in accordance with the control signal, and drives the suspension using the electric power discharged from the battery in accordance with the control signal.

The invention provides an internal combustion engine comprising a piston mounted for reciprocating linear motion within a cylinder along a cylinder axis. The piston is coupled to an output shaft by a power transfer assembly arranged to convert linear motion of the piston to rotary motion of the output shaft. The piston has a first head moveable within a first chamber and a second head opposite the first head and moveable within a second chamber. The power transfer assembly has a lubrication system for lubricating moving components of the power transfer assembly. The lubrication system is sealed from the first chamber and the second chamber to prevent the passage of fluid from the lubrication system into the first chamber and the second chamber.

Disclosed is a method for controlling a hydrofoil board powered by a motor driven propeller. The motor is controlled by a hand controller configured with user selectable operating pre-sets including a first operating pre-set, wherein the board is accelerated to a first speed which is less than that required for the board to hydrofoil, and a second operating pre-set, wherein the board is accelerated to a second speed sufficient for the board to hydrofoil. Alternatively, the operating pre-sets may limit the motor power. A system for operating a hydrofoil board is also disclosed, which includes a propulsion control unit comprising a propulsion source, and a hand controller configured to receive a first user input and a second user input and to transmit the user inputs to the propulsion control unit.

A marine vessel electric propulsion system includes an electric motor, a propulsive force generator to be driven by the electric motor to generate a propulsive force, an operator to be operated by a user to adjust the power output of the electric motor, and a controller. The controller is configured or programmed to control the power output of the electric motor based on an operation of the operator, and to change a power output gain characteristic of the electric motor with respect to an operation amount of the operator in response to a gain change command.

A jet propelled watercraft includes a reverse gate that moves to a first position and to a second position. When the reverse gate is in the first position, the reverse gate causes a vessel body to move forward. When the reverse gate is in the second position, the reverse gate causes the vessel body to decelerate or move backward. A velocity mode selector is used to select a normal mode or a velocity mode. The velocity mode has a maximum velocity different from that of the normal mode. When the reverse gate is in the second position and the velocity mode is selected, a controller is configured or programmed to set an upper limit of an engine rotation speed in the velocity mode to be different from that of the engine rotation speed in the normal mode.

A method of controlling steering loads on a marine propulsion system of a marine vessel is provided. The marine vessel has at least two sets of marine drives, each set having at least an inner marine drive and an outer marine drive, and a steer-by-wire steering actuator is associated with each set of marine drives. The method includes determining a maximum required actuator pressure on each steer-by-wire steering actuator, and determining a pressure reduction amount based on the maximum required actuator pressure. A link toe angle has been determined based on the pressure reduction amount. A mechanical link connecting each inner marine drive to the respective outer marine drive is adjusted to achieve the link toe angle.

A marine propulsion device controller includes a main operator that starts engines of all propulsion devices collectively with a simple operation and increases the degree of freedom of layout on a panel on which the main operator is disposed. The main operator is provided in common for all of the propulsion devices. The main operator receives a first operation and a second operation consecutively after receiving the first operation. All remote control ECUs are activated in response to receiving the first operation. The main operator outputs a collective start command to simultaneously start all the engines of the propulsion devices in response to receiving the second operation. Each remote control ECU starts the corresponding engine based on the collective start command.

A method for setting an engine speed of an internal combustion engine in a marine propulsion system to an operator-selected engine speed includes predicting a position of a throttle valve of the engine that is needed to provide the operator-selected engine speed, and determining a feed forward signal that will move the throttle valve to the predicted position. After moving the throttle valve to the predicted position, the method next includes controlling the engine speed with a feedback controller so as to obtain the operator-selected engine speed. The feed forward signal is determined based on at least one of the following criteria: an operator-selected control mode of the marine propulsion system; and an external operating condition of the marine propulsion system. A system for setting the engine speed to the operator-selected engine speed is also described.

A method for controlling movement of a marine vessel includes controlling a propulsion device to automatically maneuver the vessel along a track including a series of waypoints, and determining whether the next waypoint is a stopover waypoint at or near which the vessel is to electronically anchor. If the next waypoint is the stopover waypoint, a control module calculates a distance between the vessel and the stopover waypoint. In response to the calculated distance being less than or equal to a threshold distance, the propulsion device's thrust is decreased. In response to sensing that the vessel thereafter slows to a first threshold speed, the vessel's speed is further reduced. In response to sensing that the vessel thereafter slows to a second, lower threshold speed or passes the stopover waypoint, the propulsion device is controlled to maintain the vessel at an anchor point that is at or near the stopover waypoint.

A method for maneuvering a marine vessel powered by a propulsion system includes accepting inputs to an electronic navigation device and generating a desired track based on the inputs. The desired track includes a series of waypoints, each waypoint in the series of waypoints being associated with a respective heading. The method also includes sending position and orientation information corresponding to each waypoint and its associated heading to a control module. Based on the position and orientation information, the control module generates steering and thrust commands that are required to maneuver the marine vessel from a current waypoint and heading in the series to a following waypoint and heading in the series. According to the steering and thrust commands, the propulsion system thereafter propels the marine vessel along the desired track to each waypoint and its associated heading in succession. A corresponding system is also disclosed.