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.

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.

A rotary vane steering gear driven by a rotary vane hydraulic actuator, having a body confining an internal hydraulic space in the shape of toroid with a rotation axis (X-X). The body is divided by a plane (A-A) perpendicular to the rotation axis and in case of a circular torus shaped hydraulic space passing through the center point of the circle delimiting the space, the plane divides the space into a movable part (rotor 1.1) and a stationary part (stator 1.2). Both parts are bound by two thrust rings, that are fastened concentrically on the radially opposite sides of the hydraulic space, each to the respective edge of one body part and in radial overlap with the other body part, to create two concentric slewing bearings.

A rotary vane steering gear driven by a rotary vane hydraulic actuator, having a body confining an internal hydraulic space in the shape of toroid with a rotation axis (X-X). The body is divided by a plane (A-A) perpendicular to the rotation axis and in case of a circular torus shaped hydraulic space passing through the center point of the circle delimiting the space, the plane divides the space into a movable part (rotor 1.1) and a stationary part (stator 1.2). Both parts are bound by two thrust rings, that are fastened concentrically on the radially opposite sides of the hydraulic space, each to the respective edge of one body part and in radial overlap with the other body part, to create two concentric slewing bearings.

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 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.

The invention provides a device which can reduce the drag and assist the steering of the ship, mainly to set up a 3-way pipe in the bow where is below the water level. The 3-way pipe leads to three openings at the stem, the port side and the starboard side respectively. At least one control valve (or deflector) can be provided in the 3-way piping system. The valve (or deflector) can be controlled from the bridge, with a diversion device. When the ship sails forward, water flows into the 3-way pipe from the forward pipe, distributed to both side pipes and then outflow, so that it can reduce the pressure drag to the stem, improve the ship's speed and save bunker. When the valve (or deflector) is set as neutral, the water will be distributed evenly to both side pipes, which will not affect the ship's heading. When the valve (or deflector) deflects more water to either side's pipe, the ship will turn to the opposite side.

A rotary vane steering gear driven by a rotary vane hydraulic actuator, having a body confining an internal hydraulic space in the shape of toroid with a rotation axis (X-X). The body is divided by a plane (A-A) perpendicular to the rotation axis and in case of a circular torus shaped hydraulic space passing through the center point of the circle delimiting the space, the plane divides the space into a movable part (rotor 1.1) and a stationary part (stator 1.2). Both parts are bound by two thrust rings, that are fastened concentrically on the radially opposite sides of the hydraulic space, each to the respective edge of one body part and in radial overlap with the other body part, to create two concentric slewing bearings.

A rotary vane steering gear driven by a rotary vane hydraulic actuator, having a body confining an internal hydraulic space in the shape of toroid with a rotation axis (X-X). The body is divided by a plane (A-A) perpendicular to the rotation axis and in case of a circular torus shaped hydraulic space passing through the center point of the circle delimiting the space, the plane divides the space into a movable part (rotor 1.1) and a stationary part (stator 1.2). Both parts are bound by two thrust rings, that are fastened concentrically on the radially opposite sides of the hydraulic space, each to the respective edge of one body part and in radial overlap with the other body part, to create two concentric slewing bearings.

Techniques are disclosed for systems and methods to provide accurate positioning for a hydraulic steering system without a need for a steering reference transducer. A hydraulic steering system may include a logic device in communication with an autopilot pump controller. Control and sensor signals provided by the pump controller are used to determine a linear or uncompensated steering actuator speed and an estimate of the hydraulic elasticity of the steering system, which can be modeled as an estimate of the air volume trapped within the steering system. The hydraulic elasticity/air volume estimate is used to determine a corrected or compensated steering actuator speed, and the corrected steering actuator speed is used to accurately control the steering system.