Provided is a rudder assembly producing significant thrust to reduce energy consumption of vessels during voyage. The rudder assembly is formed of first/second rudder units arranged on both sides of first/second propellers. As seen from rear, each first/second rudder unit is formed of left/right rudders arranged on the left/right of the first/second propeller. Each left/right rudder of the first/second rudder units is formed of a first left/right rudder portion extending in the right-left direction, a second left/right rudder portion curved from the left/right end of the first left/right rudder portion toward lower left/right, and a third left/right rudder portion extending downwards from the lower end of the second left/right rudder portion. The first left/right rudder portions of the first/second rudder unit are arranged spaced upwardly apart from the upper edge of the tip circle of the first/second propeller for a distance of 10-20% of the diameter of the first/second propeller.

A propulsion rudder for use with a water vessel, preferably an unmanned surface water vessel. The propulsion rudder includes a rotating base, a rudder assembly, and a thrust assembly. In one embodiment, the rudder assembly may comprise two vertical mast rudders connected by an upper horizontal wing, with the thrust assembly mounted on the horizontal wing. In a second embodiment, the rudder assembly may comprise an annular airfoil with the thrust assembly mounted on a mast and positioned in the center of the annular airfoil. The thrust assembly may be a propeller, a turbine, a ramjet, or a rocket.

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.

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.

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 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 rudder device for a hydrojet vessel. The rudder device includes a mounting plate, a primary rudder and a secondary rudder coupled to a hydrojet. The primary rudder and the secondary rudder providing steerage as the hydrojet vessel is displaced through the water.

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 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.

Various aspects provide for a propulsion system (200) for a ship (100) comprising at least first and second thrusters (205, 206) and first and second directors (220, 720), wherein a computing platform (300) is coupled to the thrusters and directors being configured to receive desired longitudinal and lateral headings (750, 760) and determine a configuration of the propulsion system that is expected to propel the ship in the desired longitudinal and lateral headings.