After a week of intensive training in Panamanian waters, Boarfish transited the Panama Canal on 21 November and set out for Pearl Harbor where she arrived on 2 December.

Taietsu Maru was destroyed completely by American planes of the 14th Air Force later that same day, and Boarfish received partial credit for the sinking.

The submarine's second patrol began on 11 March 1945 when she departed Fremantle for a second tour of duty in the South China Sea.

Boarfish successfully carried out two reconnaissance missions along the east coast of French Indochina before ending her patrol in Subic Bay on 21 April.

On the 29th, Boarfish performed lifeguard duties during an Allied air strike on Singapore, and she remained off the Malay coast patrolling until 6 August, when she set course for Subic Bay.

She parted company with them on 5 September and put into Apra Harbor, Guam, where she remained until 17 November training in postwar maneuvers and drills.

Boarfish operated out of San Diego in local training exercises until 9 September, when she got underway for a tour in the western Pacific.

Commencing 30 July 1947 Boarfish was the flagship of the first exploration under the Polar Ice Cap in the Bering Strait, this mission designated as Task Group 17.3 Operation Blue Nose under the command of R. Adm. Allan Rockwell McCann for the purpose of testing the under-ice use of Sonar, developed by Dr. Waldo K. Lyon, director of the Arctic Submarine Laboratory, who was also aboard.

She left Mare Island on 21 February 1948 and steamed via San Diego, Panama, New London, Malta, and Port Argostoli, Greece, to İzmir, Turkey.

Boarfish was struck from the Naval Register on 20 May 1948, and transferred (sold) to Turkey under terms of the Security Assistance Program, 23 August 1948.