Although  both the Requin and Spinax, as initially converted, were relatively successful in their new rolls, from the very start the conversion showed flaws that were hard to ignore or overlook. Because of the submarines’ low silhouettes, the effective range of the radars was seriously handicapped and breaking seas over the deck aft caused nightmares with the SV-2 height finders.

Requin (SS-481) keel was laid down on 24 August 1944 by the Portsmouth Navy Yard, Portsmouth, N.H.; launched on 1 January 1945 and commissioned on 28 April 1945.

Following shakedown off the New England coast, Requin departed Portsmouth on 3 June 1945 en route to Hawaii. She joined the Pacific Fleet on 13 July at Balboa and at the end of the month reached Pearl Harbor. Two weeks after her arrival, however, World War II ended and Requin, by then en route to Guam, was recalled and ordered back to the Atlantic.

Requin converted to a Radar Pickett Submarine at Portsmouth Naval Shipyard, Portsmouth, NH in 1946. After leaving the yard she resumed operations in the western Atlantic and in the fall of 1947 moved north for exercises above the Arctic Circle. Reclassified (SSR-481) in January 1948, Requin was transferred to SubRon 8 at New London in June and in May 1949 sailed east for her first deployment with the 6th Fleet. Arriving at Gibraltar on 14 May, she operated in the Mediterranean until 30 June.

In October 1968 Requin began inactivation at Norfolk. Decommissioned on 3 December 1968, she was sent to St. Petersburg, Fla., in February 1969 and served there as a Naval Reserve Training ship until struck from the Navy list 20 December 1971.