was a , the first United States Navy ship to be named for the wahoo. Construction started before the U.S. entered World War II, and she was commissioned after entry. Wahoo was assigned to the Pacific theatre. She gained fame as an aggressive and highly successful submarine after Lieutenant Commander Dudley Walker "Mush" Morton became her skipper. She was sunk by Japanese aircraft in October 1943 while returning home from a patrol in the Sea of Japan.
Construction
Wahoos keel was laid down 28 June 1941 at the Mare Island Navy Yard, Vallejo, California. She was launched on 14 February 1942 (sponsored by Mrs. William C. Barker, Jr.), and commissioned on 15 May 1942 with Lieutenant Commander (LCDR) Marvin G. "Pinky" Kennedy (Class of 1929) in command. Lieutenant Richard O'Kane joined the precommissioning crew and served as her executive officer (XO) on five war patrols under Kennedy and Morton (O'Kane later received a Medal of Honor for his service in ).
Following fitting out and initial training along the California coast (which took her as far south as San Diego), Wahoo departed Mare Island on 12 August for Hawaii. She arrived at Pearl Harbor on 18 August and underwent exercise training until 21 August.
First patrol, August – October 1942
On 23 August 1942 Wahoo got underway for her first war patrol, seeking Japanese shipping in waters west of Truk, particularly in the area between the Hall Islands and the Namonuito Atoll. On 6 September, her third day in the area, Wahoo fired three Mark 14 torpedoes at her first target, a lone freighter; all missed, and the ship turned toward Wahoo, apparently with the intent to ram. The submarine dodged, fearful of counterattack from the air.
She continued to patrol the Truk area until 20 September, when she decided to leave the southwest part of the patrol area and explore south of the Namonuito Atoll. Under a bright moon and clear sky, the submarine sighted a freighter and her escort. Wahoo fired three torpedoes; all missed. A fourth hit the target, which was thought to take a port list and settled by the stern. Four minutes later, a series of three underwater explosions wracked the freighter. Wahoo was chased by the escort but escaped by radically changing course in a rain squall. Though credited at the time with a freighter of , postwar analysis of Japanese shipping records by JANAC showed no sinking at this time or place.
Wahoo continued her patrol and sighted several airplanes, a patrol boat, and a tender but was unable to close on any possible targets. On 1 October 1942, the submarine extended her patrol to Ulul Island, where she sighted several fishing boats. Within the next few days, Wahoo missed two of her best targets of the war. The first was (listed as a seaplane tender, she was in fact a mother ship to midget submarines), sailing without escort; Wahoo proved unable to reach a firing position. On 5 October, she sighted an aircraft carrier, believed to be , escorted by two destroyers. (In fact, Ryūjō had been sunk six weeks earlier in the Solomon Islands). Due to an approach lacking aggressiveness and skill, the target sailed away untouched. Two days later, Wahoo departed the patrol area. On 16 October, she made rendezvous with her escort and proceeded to Pearl Harbor, where she ended her first patrol on 17 October 1942.
She commenced refit the following day alongside submarine tender . Wahoo then shifted to Submarine Base Pearl Harbor for overhaul. There, a gun and two 20 mm guns were installed. Overhaul was completed on 2 November and, after three days' training, Wahoo was again ready for sea.
Second patrol, November – December 1942
On 8 November 1942, Wahoo got underway for her second war patrol, with Lieutenant Commander Dudley Walker "Mush" Morton also aboard for his prospective commanding officer (PCO) patrol. She arrived at her assigned area in the Solomon Islands, keeping Bougainville and Buka Island in sight. On 30 November, the submarine spotted smoke at a distance of ; it was a lightly loaded freighter or transport with an escorting destroyer on the port bow. Wahoos approach was unsuccessful, and she proceeded east of Cape Hanpan.