A controller for a watercraft controls first and second marine propulsion devices to start moving the watercraft by setting a first default angle, a second default angle, and a default thrust ratio as a first target rudder angle, a second target rudder angle, and a target thrust ratio respectively when a desired motion of the watercraft is straight sideways movement. The controller determines at least one of a first correcting angle, a second correcting angle, and a correcting thrust ratio to reduce an error between the straight sideways movement of the watercraft and an actual motion of the watercraft. The controller corrects the first target rudder angle, the second target rudder angle, and the target thrust ratio with the first correcting angle, the second correcting angle, and the correcting thrust ratio, respectively. The controller repeatedly detects the error and repeatedly updates the correcting angles and the correcting thrust ratio.

A ship propulsion system provides a first power transmission device that transmits power from an internal combustion engine to a propeller, a second power transmission device that transmits power from an electric motor to a propeller and that is mounted to the hull so as to be able to turn up and down independently from the first power transmission device, an actuator for causing the second power transmission device to turn up and down, and a control device. The control device is configured so as to be able to select a first drive mode in which the internal combustion engine is driven and the electric motor is not driven, and a second drive mode in which the internal combustion engine is not driven and the electric motor is driven. When the first drive mode is selected, the actuator is operated so that the second power transmission device turns up.

A ship propulsion system provides a first power transmission device that transmits power from an internal combustion engine to a propeller, a second power transmission device that transmits power from an electric motor to a propeller and that is mounted to the hull so as to be able to turn up and down independently from the first power transmission device, an actuator for causing the second power transmission device to turn up and down, and a control device. The control device is configured so as to be able to select a first drive mode in which the internal combustion engine is driven and the electric motor is not driven, and a second drive mode in which the internal combustion engine is not driven and the electric motor is driven. When the first drive mode is selected, the actuator is operated so that the second power transmission device turns up.

A method for controlling propulsion of at least two marine drives on a marine vessel includes monitoring an engine output indicator for each of the at least two marine drives on the marine vessel and detecting whether the engine output indicator for a subset of those at least two marine drives is below an expected value. If so, then an output restriction is imposed on at least one remaining marine drive not in the subset of marine drives, wherein the output restriction reduces an engine output of the at least one remaining marine drive to a predetermined level.

A joystick outputs an operating signal indicating a tilt amount and a twist direction of the joystick. A controller receives the operating signal and controls a marine propulsion device to output a thrust having a magnitude depending on the tilt amount. The controller changes a rudder angle of the marine propulsion device such that a watercraft turns in a direction corresponding to the twist direction. The controller reduces a speed of changing the rudder angle with an increase in the magnitude of the thrust.

A controller for a marine propulsion device determines a route on which a single or a plurality of target spots are located. The controller controls the marine propulsion device such that a watercraft moves along the route. The controller obtains a position of the watercraft, and determines whether or not the watercraft has arrived at a destination. When it is determined that the watercraft has arrived at the destination, the controller controls the marine propulsion device in a fixed spot keeping mode to keep the watercraft located at the destination.

A marine vessel maneuvering system includes an operator to receive both a propulsive force operation to change a propulsive force of a propulsion device and a steering operation to turn the propulsion device to steer a marine vessel, and a controller configured or programmed to perform a control to automatically drive the propulsion device to move the marine vessel in an automatic marine vessel maneuvering mode. The controller is configured or programmed to perform a control to transition to the automatic marine vessel maneuvering mode based on a transition operation being performed on the operator.

A marine vessel maneuvering system includes an operator to receive both a propulsive force operation to change a propulsive force of a propulsion device and a steering operation to turn the propulsion device to steer a marine vessel, and a controller configured or programmed to perform a control to automatically drive the propulsion device to move the marine vessel in an automatic marine vessel maneuvering mode. The controller is configured or programmed to perform a control to transition to the automatic marine vessel maneuvering mode based on a transition operation being performed on the operator.

A vessel speed control system includes a lever operator on which an operation is performed to increase or decrease a propulsion speed of the vessel, a transition operator on which a transition operation is performed to transition a normal operation mode to a speed control mode, and a controller configured or programmed to perform a control to prevent transition to the speed control mode even when the transition operation is performed on the transition operator during a restriction period of time including at least an acceleration/deceleration period of time during which a rotation speed of an engine or the propulsion speed of the vessel is changed by the lever operator in the normal operation mode.

A marine vessel maneuvering system includes a controller configured or programmed to perform a shift-out start control to control a shift actuator to immediately start an intermittent operation mode from a shift-out state when an intermittent operation switching control is performed to switch a normal operation mode in which a shift-in state continues to the intermittent operation mode in which the shift-in state and the shift-out state are repeated in a predetermined period of time based on a user's operation.