USS Piranha (SS-389/AGSS-389), a Balao-class submarine, was the only ship of the United States Navy to be named for the piranha. Piranha conducted six war patrols during World War II, receiving five battle stars. She was scrapped in 1970.

Piranha was laid down 21 June 1943 by Portsmouth Navy Yard in Kittery, Maine; launched 27 October 1943; sponsored by Mrs. William S. Farber; and commissioned 5 February 1944.

After East Coast training, Piranha departed Key West 3 April 1944 for the Panama Canal and her base, Pearl Harbor, arriving 18 May for final training. With Guardfish (SS-217), Thresher (SS-200), and Apogon (SS-308), she made her first war patrol between 14 June and 8 August. The coordinated attack group prowled waters west and north of Luzon, striking fiercely and with notable success at Japanese convoys. Piranha’s victims were Nichiran Maru, sunk 12 July, and Seattle Maru, sunk four days later. Several times attacked by enemy aircraft and dodging surface patrol craft, Piranha returned safely to Majuro.

For the first part of her second patrol, Piranha joined 9 other submarines in offensive reconnaissance covering the Third Fleet during the assault on Peleliu, patrolling 30 August to 25 September. When Peleliu, deemed essential for the liberation of the Philippines, had been seized, Piranha’s group dissolved and she searched for targets westward along the 20th parallel, engaging an enemy patrol craft 9 October. She endured a heavy depth charge attack, but outsmarted the patrol vessel, returning to Pearl Harbor 23 October.

During her third war patrol, again with an attack group, besides seeking worthwhile targets in the East China Sea 19 November to 13 January 1945, Piranha served as lifeguard during B-29 strikes on Kyūshū. She scored two hits on a merchantman 8 January {No.2 Shinto Maru}, only to be driven off by an escort without being able to regain attack position.

Refitted at Guam, Piranha sailed 11 February for her fourth war patrol, a classic exhibition of submarine versatility. With her attack group she sought targets on the convoy lanes from Luzon to Formosa and Hong Kong. She spent 17 days on lifeguard during airstrikes on Formosa, on 27 February sinking a junk presumably serving as aircraft spotter.

Piranha was foiled by a large fleet of fishing junks from making a rapid approach on a convoy reported leaving Hong Kong 5 March. Daringly resorting to an ancient ruse of naval warfare, she improvised an Imperial Japanese Navy naval ensign and ran it up. The deception was successful, and she threaded her way through the fishermen at flank speed, but was unable to locate the convoy.

On 9 March 1945, an unidentified plane attacked Piranha, dropping a flare and two bombs. On 11 March, a U.S. Navy PBM Mariner flying boat attacked her, dropping four bombs as she took evasive action and headed for deeper water on the surface. On 20 March, an Allied aircraft which Piranha′s crew thought was most likely a United States Army Air Forces B-24 Liberator bomber bombed Piranha as she maneuvered evasively and submerged. Piranha sustained no damage in any of the attacks.