Patent ID: 8215255

Claim:
A ship comprising: a hull having a stern portion with sides that converge toward a keel line of the ship; and a pair of twisted rudder blades arranged for steering the ship, the rudder blades coupled to the stern portion of the ship with one twisted rudder blade positioned on each side of the keel line, and each twisted rudder blade having a twist that varies over a height thereof to align with a converging flow of water in a region of the twisted rudder blade generated by a geometry of the sides of the ship when the ship travels through the water in a forward direction, an angle of the twist of each blade varying progressively in the same direction between an upper end of the rudder blade near the hull and a lower end of the rudder blade remote from the hull, and in which a chord line of a cross-sectional profile of each of the twisted rudder blades at any height is directed from a leading edge of the rudder blade to a trailing edge of the rudder blade in a direction toward the keel line of the ship.