USS Spot (SS-413) was a Balao-class submarine of the United States Navy, named for the spot, a small sciaenoid food fish of the Atlantic coast, with a black spot behind its shoulders. Construction and commissioning Spot was laid down on 24 August 1943 by the Mare Island Navy Yard at Vallejo, California. She was launched on 19 May 1944, sponsored by Mrs. A. A. Gieselmann, and commissioned on 3 August 1944, Commander William S. Post, Jr., in command. U.S. Navy service September–November 1944 Spot completed fitting out at Mare Island on 18 September 1944 and moved to San Diego for shakedown. After a yard period, Spot departed for Hawaii and arrived at Pearl Harbor on 14 November 1944. First patrol, December 1944 – January 1945 Accompanied by , Spot got underway for the Marianas on 4 December. They were joined by en route, and the trio arrived at Saipan on 15 December 1944. Two days later, the hunter-killer group headed for the Yellow Sea. On 7 January 1945, Spot sank two small trawlers with her deck gun. Four days later, she destroyed a small freighter by gunfire. On 13 January off Shanghai, the submarine sank two trawlers by shellfire, and she repeated the feat the next day. In a night sweep through the Elliott Islands on 18 and 19 January, Spot torpedoed a cargo ship and a tanker. As Spot came down the west coast of Korea, she sighted a small ship and fired her last three torpedoes. All ran shallow and missed. With only 1,300 rounds of 20 mm ammunition remaining, the submarine closed to and opened fire. The enemy made an unsuccessful attempt to ram. No one manned the Japanese ship's machine gun atop her pilot house; her top deck was in shambles; and the ship was dead in the water but not sinking. Spot waited for an hour and then sent over a boarding party of seven men to plant demolition charges and search for intelligence material. After about ten minutes on board, the party had to abandon as the ship listed to port and sank by the stern. The boarding party was recovered and one Japanese prisoner taken. The submarine returned to Midway on 30 January for a refit and training period. Second war patrol, February – March 1945 On 24 February, Spot began her second war patrol which took her, , and into the East