SHIP AND STERN SHAPE HAVING STERN DUCT

A stern shape having a stern duct 30, including a propeller 20 provided on a stern portion 15 of a ship's hull 10, and the stern duct 30 mounted in front of the propeller 20, wherein the ship's hull 10 has a V stern shape, a duct body 31 of the stern duct 30 is semicylindrical in shape, a rear edge of the duct body 31 has a shape including a parallel part 33 at a central position of its upper portion from which a semicircle substantially centering on an axis 21 of the propeller 20 is offset toward both left and right sides when the ship's hull 10 is forwardly viewed from a rear portion thereof, an inner radius of the semicircle is set in a range of 40% or more and 80% or less of a radius of the propeller 20, and a width of the parallel part 33 in a lateral horizontal direction of the parallel part 33 is set to 5% or more and 25% or less of a diameter of the propeller 20, and according to this configuration, a maximum transport efficiency can be obtained by an interference effect between the shape of the ship's hull and the propeller.