Authorized in 1916 and 1918, the Medusa (Repair Ship No. 1) was primarily designed as a "tender for battleship divisions," with a steaming radius and speed approaching that of the dreadnoughts she was to service. Her keel was laid on 2 January 1920. Redesignated as AR-1 during the fleet-wide assignment of alphanumerical hull numbers on 17 July 1920, she slid down the ways on 16 April 1923, sponsored by Mrs. Burns Poe of Tacoma, Washington. The repair ship went into commission at her building yard on 18 September 1924, with Commander Ellis Lando in command.
Equipped with spacious shop facilities that enabled her to perform sheet-metal work, plating, coppersmithing, boiler repairs, welding, foundry work, as well as repairs to things optical and mechanical, the Medusa was cited in a professional journal as "the last word in completeness and modernity" that "compared most favorably with the average navy yard." The Medusa also received an aviation-related mission as the importance of ship-based aviation and the modernization of aircraft-handling facilities on board the Fleet's battleships increased. Two officers and 20 men from Observation Squadron (VO) 2, operating as a "training school and feeder for ship-plane units," embarked as a "ship-plane repair detail" to service VO-1, which was deployed on battleships.
The Medusa , homeported at San Pedro, California, and assigned to Train Squadron 2, Base Force, amply demonstrated her range and capacities when she joined the battle Fleet as it sailed from Honolulu, Hawaii, on 1 July 1925 bound for Australia and New Zealand. The Fleet stood back in to the familiar waters of southern California on 26 September.
On occasion, because of her size, the repair ship was called on to perform transport service. When warring factions endangered American and other foreign nationals' lives and property in Nicaragua and hostilities gravitated inland, the administration decided to send Marines to restore order. As part of that movement, the Medusa embarked 7 officers and 78 enlisted men of Marine Observation Squadron 4 and its six O2B-1s, sailing on 11 May 1927 for Nicaragua. She would transport more Leathernecks to that country the following year, joining the storeship Bridge (AF-1) in July 1928.
The Medusa followed the Fleet through the 1920s and 1930s as America's neutrality became more and more precarious in the light of events in Europe and Asia. Standing in to Pearl Harbor in mid-August 1941, she was carrying out her vital support function when Japanese planes attacked the U.S. Pacific Fleet and nearby military and aviation installations on Oahu on 7 December.
At the outset commanded by her repair officer, Lieutenant Commander John F. P. Miller, the Medusa 's Sailors went to general quarters, manning 3-inch antiaircraft and .30-caliber machine guns. She fired on a Japanese Type A midget submarine sunk soon thereafter by the Monaghan (DD-354), checking fire as the destroyer closed in, bone-in-teeth, for the kill. Her machine gunners claimed the destruction of two Aichi D3A1 Type 99 carrier bombers that came within range of their Lewis guns.
In the aftermath of the surprise attack, the Medusa provided pumps to the nearby damaged seaplane tender Curtiss (AV-4), machine gun ammunition to the grounded battleship Nevada (BB-36), and rifles to soldiers from Schofield Barracks. She also aided in efforts to rescue survivors on board the capsized auxiliary Utah (AG-16). No boat that reached the Medusa's gangway went away low on fuel or with its crew hungry or thirsty.
Becoming a part of the Service Force, Pacific, with the redesignation of the Base Force effective 1 March 1942, the Medusa worked at Pearl until the increase in support operations in the South Pacific demanded her presence there. She sailed on 4 April for Havannah Harbor, Efate, where she relieved the Rigel (AR-11) 20 days later. Within a week's time, 60 of her skilled artisans were toiling in nine different working parties repairing everything from 6-inch guns to recreation center equipment. She punctuated her time at Efate with a temporary repair stint at Espiritu Santo (24 July-4 August), fabricating a temporary bow for the torpedoed light cruiser Honolulu (CL-48).
As the fleet moved, so did the Medusa . She left the New Hebrides in her wake on 27 March 1944, reaching Milne Bay, New Guinea, five days later. She then operated off Cape Sudest and Guadalcanal before reporting for duty with the Third Fleet on 15 May. By the end of June she was part of the Seventh Fleet at Manus, in the Admiralties. There, after a cataclysmic explosion obliterated the ammunition ship Mount Hood (AE-11) on 10 November, the Medusa provided necessary repairs to the badly damaged internal combustion engine repair ship Mindanao (ARG-4) and 17 units of blood plasma to her crew.
After operations in Philippine waters from January to July 1945, she worked at Manus, and then Manila. The Medusa sailed from the Philippines for the last time on 13 November, bound for the west coast that she had not seen for more than four years. With orders to report to the Nineteenth Fleet and the San Diego Group of the Inactive Fleet "for temporary duty [in] connection with laying up vessels," she reached San Pedro on 9 December.
The years of hard toil, however, had taken their toll. She was reported to be "worn beyond economical repair" on 23 May 1946, and it was recommended the next month that she be stricken and "disposed of as a hulk." With her fate determined, the Medusa seemed to resist being transferred from naval custody. The submarine rescue vessel Cable (ARS-19) failed in the first attempt to tow her from San Diego. The Cable 's sister ship, the Curb (ARS-21), however, fared better. She brought the veteran home to Bremerton, the Medusa 's birthplace, on 2 October, where the repair ship was decommissioned on 18 November.
Taken over by the U.S. Maritime Commission for disposal, the Medusa was stricken from the List of Naval Vessels on 10 June 1947. After stripping, her hulk was sold to Zidell Explorations, of Portland, Oregon, on 24 August 1950. Within a year, the Navy's first keel-up repair ship was gone.
More modern repair ships carried on the Medusa 's legacy of service to the Fleet, but none could challenge her place in the Navy's history: She had been the first of a new breed. According to Lieutenant Commander Miller, performance on 7 December 1941, when the Medusa 's men displayed "courage and conduct . . . of the highest order," showed that she could not only be a fixer, but, when the chips were down, a fighter as well.