(AH-14: dp. 15,400; 1. 520'0"; b. 71'6"; dr. 24'0"; s. 17.5 k. (tl.); cpl. 568; cl. Haven; T. C4-S-B2)
Tranquillity (AH-14) was laid down under Maritime Commission contract (MC hull 745) as Marine Dolphin on 20 August 1943 at Chester, Pa., by the Sun Shipbuilding & Drydock Co.; renamed Tranquillity on 22 June 1944; launched on 25 July 1944; sponsored by Miss Carol P. Meekins; acquired by the Navy from the Maritime Commission on 14 August 1944; converted into a hospital ship at New York City by the Atlantic Basin Iron Works; and commissioned on 24 April 1945, Capt. Merrittt D. Mullen, USNR, in command.
The hospital ship got underway for Hampton Roads on 5 May and arrived at Norfolk the next morning. Following shakedown training from 8 to 18 May and a short yard period for alterations, she stood out to sea on 6 June, bound for Hawaii; transited the Panama Canal on 14 June; and arrived at Pearl Harbor on the 27th to join the Service Force, Pacific Fleet.
On 11 July, Tranquillity proceeded to Ulithi and served as the base hospital ship from 22 July to 3 August. On the latter date, she was sent to the Palaus to take on board the survivors from cruiser Indianapolis (CA-35) which had been sunk by a Japanese submarine several days earlier. She arrived at Peleliu the next morning; embarked 166 survivors; and headed for Guam where the patients were disembarked on the 8th.
Tranquillity returned to Ulithi on 10 August but was ordered to sea the next day to rendezvous with the 3d Fleet some 350 miles off the coast of Japan. Following a fortnight with the 3d Fleet, the hospital ship headed for Guam. On the 27th, she took on 766 patients at Apra Harbor and stood out for the United States. She disembarked the patients at San Francisco on 11 September and then returned to Hawaii, arriving at Pearl Harbor on the 26th. She was attached to the "Magic-Carpet" Fleet, returning armed forces personnel from overseas bases to the United States. The ship arrived at Guam on 18 October, picked up 788 patients, and disembarked them at San Francisco on 3 November. On 9 November, the ship was reclassified as a hospital transport and redesignated APH-114. The ship made two more voyages with the "Magic-Carpet" Fleet and returned to San Francisco on 30 January 1946.
Tranquility got underway for the east coast on 18 February and arrived at Philadelphia on 22 March. Three days later, she was redesignated AH-14. Tranquillity was placed out of commission, in reserve, on 26 July 1946 and struck from the Navy list on 1 September 1961.
Tranquillity received one battle star for World War II service.