Energy-saving rudder

The invention relates to a marine component and in particular relates to an energy-saving rudder. The rudder comprises a vertical rudder plate, wherein a rudder stock in running fit with a hull is arranged at the upper end of the rudder plate; the rear segment of the rudder plate is in a regular shape with a semi-elliptical cross section from top to bottom; an upper leading edge of the rudder plate twists toward one side of a vertically symmetrical central plane of the rear segment of the rudder plate; and a lower leading edge of the rudder plate twists toward the other side of the vertically symmetrical central plane of the rear segment of the rudder plate. The rudder is characterized in that an empennage is connected at the rear end of the rudder plate, is vertically arranged and is matched with the rudder plate through hinge joint; and a transmission mechanism used for being connected with a hull is arranged on the empennage. The rudder has the advantages that the camber of the cross section of the rudder plate can be increased; the hydrodynamic performance of the rudder plate can be improved; and the rudder is beneficial to control of the ships.