USS Seahorse ( SS - 304 ) USS " Seahorse " ( SS - 304 ) , a " Balao " - class submarine , was the first submarine and second ship of the United States Navy to be named for the seahorse , a small fish whose head and the fore part of its body suggest the head and neck of a horse . The first submarine " Seahorse " ( SS - 304 ) was laid down on 1 August 1942 by the Mare Island Navy Yard , Vallejo , Calif . ; launched on 9 January 1943 ; sponsored by Mrs . Chester C . Smith ; and commissioned on 31 March 1943 , Comdr . Donald McGregor in command . First war patrol , August – September 1943 . Following shakedown along the California coast , " Seahorse " sailed to Pearl Harbor and , on 3 August 1943 , got underway for her maiden war patrol , conducted off the Palau Islands . On the morning of 29 August , while the submarine was gaining attack position on a Japan ese convoy , she was detected by escorting destroyer s and suffered minor damage from a depth charge attack . " Seahorse " scored three torpedo hits on a transport on 6 September , and then went deep to evade a depth charge attack that caused severe leaks and put her number four torpedo tube out of commission . A week later , she expended eight torpedoes in an unsuccessful attempt to sink a large tanker . The submarine terminated her first patrol at Midway on 27 September . During this patrol , " Seahorse " s commanding officer ignored several potential targets , rather than face sonar - equipped escorts , which unrealistic prewar training indicated was virtual suicide . Second war patrol , October – December 1943 . Following refit , " Seahorse " sailed on 20 October for her second war patrol . Between 29 October and 31 October , the submarine sank three enemy trawlers in surface actions and then commenced a two - day attack on a 17 - ship convoy . Early on the morning of 2 November , following an attack on the convoy by another United States submarine , " Seahorse " evaded three escort ships and launched three torpedoes into two freighters . Four hours later , she again attacked , sending three torpedoes toward a tanker and another spread at a third freighter . Flames burst from each target as two Japanese destroyers turned toward " Seahorse " but too late to catch the rapidly departing submarine . Sunk in this action were the 7 , 089 - ton cargo ship " Chihaya Maru " , and the 5 , 859 - ton cargo ship , " Ume Maru " . " Seahorse " later closed again on the convoy but was driven down by depth charges and departed the vicinity . On 22 November , " Seahorse " skillfully maneuvered past three enemy escorts , launched four torpedoes from periscope depth , and sank the cargo ship , " Daishu Maru " . On 26 November , the submarine contacted another enemy convoy and began to close the range . Determined to mount an attack before the targets entered the mined Tsushima Strait , the submarine launched four torpedoes at long range quickly sinking a cargo ship ; and then , dodging enemy escorts , let go four stern shots at a second target . The results seemed disappointing — until a sudden blast sent flames and debris mushrooming high into the air , completely destroying the 7 , 309 - ton tanker , " San Ramon Maru " . " Seahorse " expended the last of her torpedoes on the night of 30 November and 1 December . After maneuvering for several hours , the submarine was finally able to fire her stern tubes at an enemy convoy . However , one torpedo exploded just after it left the tube , and the entire convoy opened fire on the vicinity of the submarine . With so many explosions around her , it was impossible for " Seahorse " to determine whether any torpedoes had hit . Low on fuel and out of torpedoes , the submarine returned to Pearl Harbor on 12 December from a successful second patrol , with five ships and three trawlers sunk . Third war patrol , January – February 1944 . " Seahorse " departed Pearl Harbor on 6 January 1944 for her third war patrol . On 16 January , while en route to the Palaus , she evaded four escorts and destroyed the 784 - ton cargo ship , " Nikkō Maru " , with three torpedo hits . She spent 21 January tracking two enemy cargo ships in company with three escorts . In the late evening , she pressed home four consecutive attacks to sink the 3 , 025 - ton cargo ship , " Yasukuni Maru " , and the 3 , 156 - ton passenger - cargo ship , " Ikoma Maru " . On the evening of 28 January , " Seahorse " began an 80 - hour chase of an enemy convoy off the Palaus . After being continually harassed by escorts and aircraft throughout the next day , " Seahorse " launched three torpedoes at the cargo ship , " Toko Maru " . After the sinking , the submarine lost contact with the convoy for several hours , but again had it in sight at dawn on 31 January . Early on the morning of 1 February , " Seahorse " launched four torpedoes for no hits followed by two more , again without result . With the crew exhausted from the extended chase , the submarine fired her final two torpedoes and headed for deeper water . After evading the escorts , she surfaced in time to see the results of her latest attack as the cargo ship , " Toei Maru " , slipped beneath the waves . " Seahorse " terminated her third patrol at Pearl Harbor on 16 February . Fourth war patrol , March – May 1944 . " Seahorse " ' s fourth war patrol was conducted in the Marianas . She departed Pearl Harbor on 16 March and intercepted a large enemy convoy on 8 April . After nightfall , the submarine launched four torpedoes at overlapping targets , sinking the converted seaplane tender , " Aratama Maru " . Shortly thereafter , her second spread of torpedoes sank the cargo ship , " Kizugawa Maru " . Although a counterattack by escorting destroyers drove the submarine from the vicinity , she quickly regained contact and continued the chase into the following day , sinking the cargo ship , " Bisaku Maru " . " Seahorse " took up lifeguard station for the carrier airstrikes on Saipan that commenced on 12 April and , while west of Saipan on 20 April , sighted and sank the Japanese submarine , " RO - 45 " . In the same vicinity a week later , " Seahorse " sank the 5 , 244 - ton cargo ship , " Akigawa Maru " . The submarine departed her lifeguard station on 3 May to refuel at Milne Bay , New Guinea , and arrived at Brisbane , Australia , on 11 May . Fifth and sixth war patrols , June – October 1944 . " Seahorse " put to sea for her fifth war patrol on 11 June 1944 , patrolling between Formosa and Luzon . On the morning of 27 June , she sank the tanker , " Medan Maru " , and damaged two other enemy vessels ; and , on 3 July , sank the cargo ship , " Nitta Maru " , and the passenger - cargo ship , " Gyoyu Maru " . The following day , the submarine expended the last of her torpedoes sinking the cargo ship , " Kyodo Maru No . 28 " , and returned to Pearl Harbor on 19 July . " Seahorse " spent the first part of her sixth war patrol supporting the capture of the Palaus and then headed for the Luzon Strait . Despite intensive efforts , the submarine could locate only one worthwhile target , " Coast Defense Vessel No . 21 " , a frigate of 800 tons , which she sank . Five days later , " Seahorse " took up lifeguard station for the carrier airstrike on northern Luzon and then returned to Midway on 18 October . Seventh and eighth war patrols , March – August 1945 . Upon completion of an overhaul at Mare Island Navy Yard , " Seahorse " put to sea on 9 March 1945 for her seventh war patrol . Following patrol in the Tsushima Strait , she sank a small junk with gunfire on 8 April . On 18 April , an attack by two patrol boats left the submarine ' s interior a shambles of broken glass , smashed instruments , and spilled hydraulic oil . " Seahorse " made hasty repairs and headed for Apra Harbor , Guam , and then to Pearl Harbor for overhaul . " Seahorse " put to sea for her eighth and final war patrol on 12 July . When hostilities ceased on 15 August , the submarine was on station southeast of Hachijo Shima . Following her return to Midway , " Seahorse " sailed for Mare Island where she was decommissioned on 2 March 1946 . She was assigned to the Pacific Reserve Fleet and remained inactive for the remainder of her career . She was reclassified an auxiliary submarine , AGSS - 304 , on 6 November 1962 , struck from the Navy list on 1 March 1967 , and sold on 14 December 1968 to Zidell Explorations Inc . , Portland , Oregon , for scrapping . " Seahorse " ( SS - 304 ) received nine battle star s for World War II service .