Abstract: A water tight prehung door for a ship bulkhead, the door being formed from a plate with a peripheral band welded thereto, being stiffened by a plurality of channels extending from one side of the door to the other and having elongated dimples in the plate disposed between the channels; a double directional gasket which buckles when closed is contained in a partial enclosure and cooperates with a dogging mechanism utilizing a parallel bar linkage which moves rollers over wedge shaped lugs to dog the door closed and form a water tight seal irrespective of which side of the door is subjected to pressure.