U.S. Navy Submariner Photo and Dogtag

I found this photo at an estate sale this past weekend. It is of a U.S. sailor, a crew member on what may be a Gato class submarine. In the background you can see the 40mm Bofors cannon on the rear deck behind the conning tower. The Gato class submarine was the backbone of the submarine fleet, and was responsible for sinking many Japanese merchant ships and warships as well. Also found with the photo was a USN dogtag which I assumed belonged to the man in the photo. I may be wrong about the type of submarine, if anyone is familiar with U.S. submarine classes your input would be appreciated.