PURPOSE: To enhance the controllability of ship steering, by providing a ship turning device which enable a ship to be turned by jetting the stream of water in a desired direction, in the head part of the ship.

CONSTITUTION: In the head part of a ship, there are provided a first hollow cylinder 6 and a second hollow cylinder 9 which are adapted to change the jetting direction of water stream discharged from a pump (not shown), and which are positionally adjusted by actuating a hydraulic drive unit 9a so that jet ports 13, 6d formed in the cylinders 6, 9 are met together for selecting the jetting direction of water stream. The jet ports 13, 6d are connected to jet pipes 14, 15, 17 from which water stream is jetted into the underwater for optionally turning the ship.