The Gato-class submarine was the state of the art in American design at the start of World War II. Using the previous Tambor-class submarine as a basis, Gatos incorporated improvements to increase their overall patrol and combat abilities. Modifications to the diesel engines and batteries increased patrol duration over Tambors, and internal alterations provided more amenities for the crew. The class is named after its lead ship, USS Gato. The stern of the Gato. Typical of the remainder of the class and of the two subsequent classes, Balao and Tench, two of the four torpedo tube muzzles are seen here. The structure above and forward of the tubes is the starboard screw guard. It prevented the stem from bumping against something that would damage the screw, seen below. Forward of the wooden tapered structure was the starboard stern plane. Between it and the port plane was the rudder. The bow of Gato. The hole in the bow to the left of the photo is the "bullnose," more properly called the towing fairlead. The openings near the waterline near the bow are flood ports for the bow buoyancy tank. Aft of the last opening is the anchor recess followed by the port bow plane folded against the superstructure. On the deck forward of the bridge (round windows), with the "y" shaped yoke atop, is the forward radio antenna stanchion. The round object just to the left of the base of this stanchion is the forward torpedo room hatch cover. The high bridge enclosure and 'aired periscope supports are visible further aft.