USS Sennet ( SS - 408 ) USS " Sennet " ( SS - 408 ) , a " Balao " - class submarine , was a ship of the United States Navy named for the sennet , a barracuda . " Sennet " was laid down on 8 March 1944 by the Portsmouth Navy Yard in Kittery , Maine ; launched on 6 June 1944 , sponsored by Mrs . Roscoe W . Downs ; and commissioned on 22 August 1944 , Commander George E . Porter in command . " Sennet " was fitted out by 18 September . She held training exercises and torpedo - tube testing off the coast of Connecticut and Rhode Island until 22 October . The submarine then tested mines and torpedoes for the Mine Warfare Test Station , Solomons Island , Md . On 11 November , " Sennet " proceeded to the operations area off Balboa , C . Z . , and conducted further training exercises . The submarine departed Balboa on 29 November for Pearl Harbor and arrived there on 16 December 1944 . " Sennet " ' s topside armament was increased to two guns , two 40 millimeter guns , and three . 50 caliber machine guns before departing Pearl Harbor for her first war patrol on 5 January 1945 . First and second patrols , January – March 1945 . " Sennet " patrolled north of the Bonin Islands until 28 January . She made two attacks on a large tanker with three escorts on 21 January but scored no hits . The following week , the submarine sank one 500 - ton picket boat and damaged another . " Sennet " refitted at Saipan from 31 January to 7 February when she began her second war patrol off southern Honshū , Japan . On 13 February , two 300 - ton picket boats were sunk by the combined gunfire of " Sennet " , , and . Three days later , the submarine attacked an enemy minelayer , the " Nariu " , with an offset spread of torpedoes from her stern tubes and went deep , to . Two torpedoes were heard to explode . While going deep , " Sennet " was rocked hard by two aircraft bombs which exploded beneath her . The submarine surfaced an hour later and saw a large oil slick and approximately 40 Japanese clinging to debris but no trace of the " Nariu " which had sunk . Third and fourth patrols , April – August 1945 . " Sennet " was refitted by in Apra Harbor , Guam , 9 March – 2 April . Patrolling off Honshū again from 3 April to 16 May , she was surfaced off Miki Saki on 16 April when she was twice straddled by torpedoes fired from patrol boats . Three days later , the submarine torpedoed and sank the cargo ship , " Hagane Maru " . On 22 April , " Sennet " attempted to save a P - 51 pilot who had bailed out near her but the man went under only from the ship . Attempts to find him were in vain . A repair ship was attacked on 28 April with two electrical torpedoes . The first blew the bow off and the second hit under the mainmast . " Hatsushima " sank by her stern . On 1 May , " Sennett " fired five steam torpedoes at an " Asashio " - class destroyer but it maneuvered and avoided them . At the end of this patrol , the submarine sailed to Pearl Harbor for upkeep and leave . " Sennet " ' s most profitable patrol was from 1 July to 9 August in the Sea of Japan . During the patrol , she sank one passenger - cargo ship , two cargo ships , and one tanker totaling 13 , 105 tons . 1945 – 1951 . When the war ended in the Pacific , " Sennet " was assigned to the Atlantic Fleet and operated from New London , Conn . In June 1946 , she was reassigned to Submarine Squadron 6 ( SubRon 6 ) at Balboa , C . Z . From 10 December 1946 to 13 March 1947 , " Sennet " participated in Operation Highjump , the third Byrd Antarctic Expedition . " Sennet " used the first basic under - ice SONAR to establish the feasibility of United States under - ice operations . " Sennet " operated from Balboa until 1949 when she was assigned to operate from Key West , Fla . , as a unit of Submarine Squadron 12 ( SubRon 12 ) . The ship conducted training for submarine and antisubmarine personnel at Key West and Guantanamo Bay , Cuba . In 1951 , " Sennet " was converted to a Fleet Snorkel submarine at the Philadelphia Naval Shipyard and returned to her homeport . 1954 – 1973 . On 4 November 1954 , " Sennet " departed Key West on her first deployment to the Mediterranean and service with the 6th Fleet . From her return on 30 January 1955 , until 1 August 1959 , the submarine conducted training , local , and fleet operations with her squadron . On the latter day , " Sennett " was reassigned to SubRon 4 and stationed at Charleston , S . C . For the next nine years , the submarine operated from Charleston with the Atlantic Fleet . She operated along the east coast , in the Caribbean , and in the Atlantic with her squadron until mid - 1968 . In November of that year , the submarine was found unfit for further Naval service . " Sennet " was struck from the Navy list on 2 December 1968 . On 18 May 1973 , her hulk was sold to Southern Scrap Material Co . Ltd . , New Orleans , La . Honors and awards . " Sennett " received four battle star s for World War II service .