(AO‑127: dp. 21,880; l. 524'; b. 68'; dr. 30'; s. 16.5 k.; cpl. 52; a. none; cl. Mission Buenaventura; T.T2‑SE‑A2)
A merchant name retained. A Franciscan mission in California founded in 1772.
Mission San Luis Obispo was laid down 18 April 1944 under a Maritime Commission contract by Marine Ship Corp., Sausalito, Calif.; launched 18 June 1944; sponsored by Mrs. George A. Patterson; and delivered 15 July 1944.
Chartered to Pacific Tankers, Inc. for operations, she spent the remainder of the war carrying fuel to our forces in the Pacific. She remained in this capacity until 27 March 1946, when she was returned to the Maritime Commission and laid up in the Maritime Reserve Fleet at James River, Va.
Acquired by the Navy 24 October 1947, she was placed in service with the Naval Transportation Service as Mission San Luis Obispo (AO‑127). She was transferred to the operational control of the newly created Military Sea Transportation Service 1 October 1949 as USNS Mission San Luis Obispo (T‑AO‑127). She served with MSTS until 22 June 1955, when she was returned to the Maritime Administration and laid up in the Maritime Reserve Fleet at Olympia, Wash.
Reacquired by the Navy 27 June 1956, she was placed in service with MSTS and served until 24 June 1957, when she was returned to the Maritime Administration and laid up in the Maritime Reserve Fleet at Beaumont, Tex. She was struck from the U.S. Naval Vessel Register 24 September 1957.
Sold to the Hudson Waterways Corp. 25 March 1966 for conversion into a combination containership and train ferry, she was renamed Seatrain Puerto Rico 1 April 1966. Upon completion of conversion, Seatrain Puerto Rico was assigned the duty of carrying cargo between the Caribbean and the east coast of the United States and occasionally to Vietnam.