The USS Sea Cat (SS-399) was a Balao-class submarine built by the Portsmouth Navy Yard and commissioned on 16 May 1944. Following a shakedown cruise, the Sea Cat traveled to the Souther China Sea to begin operation in a wolf pack with the submarines USS Pampanito (SS-383), Pipefish (SS-388), and Sea Raven (SS-196).
While her commanding officer was convinced that her torpedoes found their mark against two merchant ships, postwar Japanese records dispute the claim. By winter, a tired Sea Cat crew sailed into Guam having spent 61 days at sea.
In February of 1945, the Sea Cat set out in the East China Sea as part of a wolf pack. The submarines operated off the coast of Japan, using gunfire to attack and damage a 300-ton cargo vessel. The Sea Cat also reported sinking a 2,000-ton cargo ship with torpedoes. Postwar records, however, do not back up this claim. The patrol came to a close of 24 March 1945 and she was not to set out again until 27 April 1945.
During her next patrol in the Yellow Sea, the Sea Cat employed expert gunfire to destroy 400 tons of enemy shipping and also rescued two enemy sailors from the wreckage of their sinking vessels.
The Sea Cat sailed for the Kuril Islands but before she could engage the enemy, the Japanese had surrendered. The Sea Cat had the honor of taking part in the surrender ceremonies in Tokyo Bay on 2 September 1945.
After the war, the Sea Cat was transferred to the Atlantic Fleet and spent two years in the Panama Canal Zone. The Sea Cat was transferred to Key West, Florida in June 1949 where she was redesignated AGSS-399 and reconfigured for her new research role. In January 1952, she was converted into a fleet snorkel submarine and returned to her original designation of SS-399. In July 1966, she took part in a four-month deployment to the Mediterranean Sea with the 6th Fleet. The Sea Cat was stricken from the Navy List on 2 December 1968 and sold five years later on 18 May 1973.