A boat includes a planing hull, a propeller, a main rudder, and a pair of flanking rudders. The planing hull has port and starboard sides, a transom, a hull bottom, and a centerline running down the middle of the boat, halfway between the port and starboard sides. The propeller is positioned forward of the transom and beneath the hull bottom. The main rudder is positioned aft of the propeller. The main rudder has a rotation axis about which the main rudder rotates. The flanking rudders are positioned forward of the propeller. One of the flanking rudders is positioned on the port side of the centerline, and the other flanking rudder is positioned on the starboard side of the centerline.

A maneuvering system for a ship provided with, in the stern, a port-side propulsion system, and a starboard-side propulsion system. For controlling the system, a forward or backward force of the ship 1 is obtained by the difference between the forward and backward propulsion forces of the propulsion systems and a first turning moment in a turning direction of the ship generated by the propulsion forces is offset by a second turning moment in the turning direction of the ship generated by steering a port-side rudder, whereby the ship moves in a transversal manner toward its starboard side while rotation of the ship is avoided. A high degree of maneuverability is thereby achieved with a relatively simple maneuvering operation.

A steering system for a marine vessel comprises a helm, a control head, and a joystick. The helm and control head may respectively provide user inputted steering commands and user inputted shift and throttle commands on a first CAN network. The joystick and the control head may respectively provide user inputted steering commands and user inputted shift and throttle commands on a second CAN network. The helm may provide user inputted steering commands on the first CAN network. The control head may provide user inputted shift and throttle commands on the second CAN network. The joystick may provide user inputted steering commands and user inputted shift and throttle commands on either the first CAN network or the second CAN network.

An autopilot system for automatically steering a marine vessel is disclosed. The marine vessel comprises two electric motors connected to respective propulsors, two rudders, a rudder steering mechanism and a navigation system for determining the vessel position with respect to an intended course. The autopilot system can operate according to one or more autopilot modes comprising at least a motor steering autopilot mode wherein the autopilot system is configured to automatically control the rudder steering mechanism in order to lock the rudders at a fixed angle, and based on a feedback from the navigation system to independently and dynamically adjust power supply to each of the propulsors by independently and dynamically regulating electric power supply to the respective electric motors in order to maintain the vessel on course.

In collision-avoidance maneuvering in congested waters, an own ship is decelerated by astern power. The own ship is continuously navigated on a current target course with a propulsion propeller always rotated forward at the stern of the own ship. The astern power is generated as the propulsion of a propeller slipstream with rudder angles formed at a pair of right and left high-lift rudders disposed behind the propulsion propeller. In the decelerating maneuvering, the rudder angles formed at the high-lift rudders are controlled within a range from a rudder angle for applying a maximum propeller slipstream as the astern power to a rudder angle for eliminating the ahead power of the propeller slipstream, and the deceleration of the own ship is controlled by changing the astern power according to the rudder angles.

This disclosure describes flanking rudders, including asymmetrically shaped flanking rudders and methods of manufacturing and using asymmetrically shaped flanking rudders. An exemplary asymmetrically shaped flanking rudder includes an exterior surface having a first shape and an exterior surface having second shape different from the first shape.

A steering device allows a ship to travel efficiently. A port side rudder plate has a left front rudder plate fixed to a lower portion of a stern and a left rear rudder plate. A starboard side rudder plate has a right front rudder plate fixed to the lower portion of the stern and a right rear rudder plate. The left rear rudder plate is supported by a rear portion of the left front rudder plate and a left steering shaft fixed to the left rear rudder plate. The right rear rudder plate is supported by a rear portion of the right front rudder plate. A right steering shaft fixed to the right rear rudder plate. In a rear view, lower end portions of the port side rudder plate and the starboard side rudder plate are at a lower end portion of an outer peripheral portion of the propeller.

A remotely-controlled observation vehicle for observing swimmers is disclosed. The vehicle is designed to float and move on the water, and includes a hull, which is typically sealed. An above-water camera mount is attached to the hull and extends upwardly from it. The above-water camera mount carries one or more cameras. A below-water camera mount is attached to the hull and extends downwardly from it. The below-water camera mount also carries one or more cameras. A first propulsion system is adapted to drive the vehicle through water, and a first steering system is associated with the first propulsion system. The observation vehicle also includes communication and control systems. The vehicle may be fore-aft symmetrical, with a propulsion system and a steering system disposed proximate to each end of the hull. Also disclosed is a system including a vehicle with an associated controller and a data review station.

A digital twin computation section collects a speed of an own ship, a position of the own ship, and a heading of the own ship in real time, and reproduces an actual hull motion of the own ship realized at a current steering angle on a navigational electronic marine chart. A simulation computation section displays, on the navigational electronic marine chart, an assumed hull motion of the own ship determined by calculation that assumes that a force acting on the hull is a driving force at the current steering angle. A resultant force of external forces computation section calculates an acting direction and a magnitude of a resultant force of external forces acting on the hull based on a ship speed difference, ship position difference, and heading difference between the actual hull motion and the assumed hull motion.

A boat includes a planing hull, a propeller, a main rudder, and a pair of flanking rudders. The planing hull has port and starboard sides, a transom, a hull bottom, and a centerline running down the middle of the boat, halfway between the port and starboard sides. The propeller is positioned forward of the transom and beneath the hull bottom. The main rudder is positioned aft of the propeller. The main rudder has a rotation axis about which the main rudder rotates. The flanking rudders are positioned forward of the propeller. One of the flanking rudders is positioned on the port side of the centerline, and the other flanking rudder is positioned on the starboard side of the centerline.