USS Flounder (SS-251), a Gato-class submarine, was the only ship of the United States Navy to be named for the flounder. Construction and commissioning Flounder′s keel was laid down by the Electric Boat Company in Groton, Connecticut, on 5 December 1942. She was launched on 22 August 1943, sponsored by Mrs. Astrid H. McClellan, and commissioned on 29 November 1943. First and second war patrols Flounder arrived at Milne Bay, New Guinea, from New London, Connecticut, on 6 March 1944, and 11 days later sailed on her first war patrol, bound for the Palau Islands. Many planes were sighted, limiting her action, and few contacts were made. She returned to Milne Bay to refit, then sailed to Manus for training, and from that base took departure 3 June on her second war patrol. In the Philippine Sea during the assault on the Mariana Islands, Flounder made a sound contact on 17 June which resulted in her sinking the 2,681-ton transport Nipponkai Maru. Escorts immediately began a persistent, vigorous, but ineffective counter-attack. On 24 June, as Flounder sailed on the surface, two enemy planes suddenly dived out of the cloud cover, and dropped bombs which landed close aboard, causing some minor damage. The submarine topped off her fuel tanks at Manus 6 July, and sailed on to Brisbane, Australia, to refit. Third, fourth and fifth war patrols Flounder cleared Brisbane on her third war patrol 1 August 1944, and after calling at Manus on 8 and 9 August, sailed on to serve as lifeguard during strikes on the Philippine Islands. Once more, during the portion of her patrol devoted to aggressive patrol, she found few contacts, and was able to make only one attack. The intended target, a small escort, dodged her torpedoes, and drove her deep with depth charges. Flounder took on provisions and fuel at Mios Woendi, New Guinea, from 28 August to 1 September, then completed her patrol in Davao Gulf, returning to Brisbane on 4 October. On her fourth war patrol, for which she sailed on 27 October 1944, Flounder patrolled the South China Sea with two other submarines, north of Lombok Strait on November 10. Flounder sighted what was first thought to be a small sailboat. Closer inspection revealed the target to be the conning tower of a submarine, and Flounder went to battle stations submerged. She sent four torpedoes away, observing one hit and feeling