https://creativecommons.org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse
Sea Robin (SS-407) during shakedown training off Portsmouth, N.H., 4 September 1944. She mounts a single 5"/25 caliber dual-purpose gun abaft the conning tower, with single 20-millimeter guns forward and aft of the bridge.
US Navy photo from DANFS, courtesy of Joe Radigan, MACM USN, Ret.