A new DC motor drive release was designed, built, and tested at sea. The conventional motor drive release was worked by DC motor driving a detent attached on the shaft. In this composition, the frictional force between detent and lever increased according as the water pressure increased in the deep ocean. Therefore, an accident which the release did not work occasionally happened and it was unreliable. A new release is worked by DC motor driving a pin connected to the nut along the axis of the screw inward the pressure hull using a sending screw. In the new composition, water pressure works effectively to release. A ball screw is used in order to decrease frictional force as the sending screw. A frictional brake is also used to hold the hook with a pin and for itself not to move by water pressure. The release is worked by acoustic command.