The second USS Argonaut (SS-475) was a Tench-class submarine. Her keel was laid at Portsmouth Navy Yard on 28 June 1944. She was launched on 1 October 1944 sponsored by Mrs. Allan R. McCann and commissioned 15 January 1945, with Lieutenant Commander John S. Schmidt in command.
Argonaut held shakedown in the Portsmouth area and in Narragansett Bay and returned briefly to Portsmouth on 27 March for post-shakedown availability. She then sailed on 14 April for Key West, Florida, where she conducted special tests for lighter-than-air craft and training operations with the Fleet Sound School. Argonaut departed the Florida coast on 13 May to transit the Panama Canal en route Hawaii. Reaching Pearl Harbor on 11 June, the submarine spent two weeks in repairs and training exercises before beginning her first war patrol on 28 June.
She made a fuel stop at Saipan on 10 July and then proceeded to the Formosa Strait and the East China and Yellow Seas to search for enemy shipping. On 16 July, Argonaut spotted a downed aviator, picked him up, and later transferred him to . Her only contact with Japanese vessels during the patrol came on 12 August, when Argonaut sank a 25-ton junk with fire from her 40-millimeter and 20-millimeter guns. Since she terminated her patrol at Guam on 21 August, six days after Japan capitulated, this was her only combat action during World War II.
Argonaut departed Guam on 1 September and proceeded, via Pearl Harbor and the Panama Canal, to Tompkinsville, New York. She arrived in New York on 4 October but continued on to Kittery, Maine, for an overhaul. Early in 1946, Argonaut was assigned to the Atlantic Fleet and was based at Panama. While en route to Panama, Argonaut collided with off the eastern coast between New York City and Philadelphia, Pennsylvania, during a heavy fog. Both ships sustained minor damage and Argonaut continued on to Panama. Later in 1946, Argonaut became a unit of SubRon2 based at New London, Connecticut.
In July 1952, the submarine underwent a major conversion at the Philadelphia Naval Shipyard, during which she received a snorkel system and a streamlined conning tower. These changes gave the submarine greater underwater endurance. Argonaut operated from New London until July 1955, when she was reassigned to SubRon6 at Norfolk, Virginia. Following this move, Argonaut was converted to a guided-missile submarine armed with a Regulus I missile.
In 1958, Argonauts home port was changed to San Juan, Puerto Rico, where she remained for a year, engaged primarily in missile operations. The submarine returned to Norfolk, Virginia, in 1959. During an overhaul in early 1960, Argonauts missile equipment was removed. When the alterations were completed, the submarine resumed her routine of supporting antisubmarine warfare (ASW) training operations out of Norfolk.
On 15 October 1962, Argonaut performed duties in conjunction with the naval quarantine of Cuba. She then had a routine overhaul at the Norfolk Naval Shipyard. The yard work was completed on 13 May 1963, and the submarine sailed to the New London area for refresher training. After further training in the Virginia Capes area, she got underway on 19 August for the Mediterranean and service with the Sixth Fleet. Her ports of call during the deployment included Gibraltar; Suda Bay, Crete; Rhodes, Greece; İzmir, Turkey; Toulon, France; Marseille, France; Sanremo, Italy and Naples, Italy. The submarine returned to home port on 15 December.
Argonaut continued her routine of operations along the east coast with periodic deployments to the Mediterranean through 1 December 1965. On that day, she commenced overhaul at the Norfolk Naval Shipyard. Argonaut left the shipyard on 10 June 1966, for sea trials and, on 20 January headed for New London for refresher training. She then provided services to the submarine school at New London through the remainder of 1966.
The submarine moved to Norfolk early in 1967 but left the Virginia Capes area on 9 January, bound for San Juan, Puerto Rico. Argonaut took part in Operation "Springboard" through the rest of January and most of February before leaving the Caribbean on 23 February to return to Norfolk, arriving there five days later. During the next two months, Argonaut prepared for a North Atlantic and Mediterranean cruise. She sailed on 26 May and made her first port call at Trondheim, Norway. The submarine also visited Cuxhaven, Germany; Leith, Scotland; Rota, Spain; Naples, Italy; and Valletta, Malta, before returning to her home port on 20 September. She remained in the local operating area through the duration of the year.
The submarine traveled to New London on 6 February 1968, entered drydock there on 9 February, and remained in it through 26 February. Argonaut left the keelblocks on 27 February and returned to Norfolk. She made a patrol in the Jacksonville, Florida operating area in mid-March and put in at Port Everglades, Florida, on 22 March. Three days later the submarine got underway for her home port. Upon her arrival in Norfolk on 29 March, she assumed a schedule of local operations. This was interrupted by another cruise to Port Everglades in October. She returned that month to Norfolk and began preparations for deactivation. Argonaut was decommissioned on 2 December, and her name was struck from the Naval Vessel Register that same day. She was sold to Canada and commissioned 2 December 1968, in the Royal Canadian Navy as Rainbow (SS-75) and decommissioned 31 December 1974.
Argonaut won one battle star for her World War II service.