US Navy service
Quirigua was delivered to the War Shipping Administration (WSA) for potential wartime service at New York on 2 June 1941 under bareboat charter and simultaneously delivered by WSA to the Navy Department under the same terms.[19][20][21] The original charter to WSA expired on 30 June 1943 but was renewed at Sydney, Australia, on 22 November 1943 retroactive to the expiration.[19]
Brewer's Drydock Co. of Staten Island, New York converted the ship for Navy service.[20] The library was converted to office space, the main dining room was converted to a mess hall, the luxury lounge became the officer's wardroom. Staterooms, the verandah cafe and ever other available space was packed with standee berths. Some hold space became ammunition storage and naval alarm and electrical systems, including degaussing, were added. Some 800 tons of concrete ballast was also poured into the ship.[15] Armament was added with a single 5"/38 caliber gun, four 3"/50 caliber guns on raised platforms fore and aft for anti-aircraft (AA) and anti-submarine use and up to eight Oerlikon 20 mm cannon AA guns.[20][22]
On 14 June 1941 the ship was commissioned as Mizar into the US Navy under the command of Cmdr E.D. Walbridge.[20] Mizar was with Task Force 16 in August 1941 composed of the battleship USS Mississippi (BB-41), heavy cruisers USS Quincy (CA-39) and USS Wichita (CA-45), five destroyers, transports when joined by the carrier USS Wasp (CV-7), the heavy cruiser USS Vincennes (CA-44) and escorts all bound for Iceland with the first occupation troops.[23] The ship left Reykjavik on 12 August 1941 in convoy with the other transports and escorts.[24] Mizar was back in Iceland at Hvalfjordur in May 1942 where she supplied the battleship USS Washington (BB-56) and other ships of Task Force 99.[25] For the next year Mizar operated in the western Atlantic from a number of US East Coast ports supplying bases and ships from Iceland to the Virgin Islands.[20]
Mizar was then modified with more berthing before departing from Norfolk, Virginia, 10 June 1942 with task force TF 39, carrying the 1st Parachute Battalion attached to the 1st US Marine Division who were to take part in the invasion of the Solomon Islands. The force transited the Panama Canal on its month-long voyage to Wellington, New Zealand arriving on 11 July 1942.[20][26]
Continuing in the southwest Pacific as part of Service Force, US 7th Fleet, she operated initially from Australian ports supporting the successful Australian and American campaign to stop the Japanese on New Guinea.[20] The Army forces engaged in the New Guinea campaign were suffering a critical shortage of fresh food requiring refrigerated transport. In August 1943 the Navy made unused refrigerated space in Mizar available on trips into Milne Bay, New Guinea to help meet Army requirements giving some relief as the Army sought more refrigerated space in its own vessels assigned to the South West Pacific Area.[27] Mizar made seven unescorted voyages to San Francisco, California, between 12 October 1942 and 9 February 1945 to get fresh meat, fruit, vegetables, dairy products and eggs to supply advanced bases and combatant ships. When not making these crossings of the Pacific Ocean she normally worked between Brisbane and Milne Bay.[20]
After the advance of US and Allied Forces in the Pacific she extended her Australian-based service to the Admiralty Islands in May 1944 and anchored in Leyte Gulf in the Philippines on 18 February 1945. She continued carrying men and supplies throughout these areas until 4 January 1946.[20]
Mizar reached San Francisco 25 January 1946 making her last Pacific crossing but soon received orders to go to the US East Coast. Previewing a return to civilian status, en route she took bananas for the United Fruit Company from Quepos, Costa Rica to Charleston, South Carolina.[20]
Mizar averaged over 5,000 miles a month in World War II and received four battle stars for her service. She was decommissioned as a naval vessel at Baltimore, Maryland on 1 April 1946, and struck from the Navy list of active ships on 17 April.[20] The War Shipping Administration took possession of the ship on 1 April at Baltimore placing it under General Agency Agreement for operation by United Fruit in preparation for its return to commercial service.[19]
