ARL-12
Displacement 4,100
Length 328'
Beam 50'
Draw 14'
Speed 12 k
Complement 253
Armament 8 40mm, 8 20mm
Class Achelous

Poseidon (ARL-12) was laid down as LST-1037 by the Boston Navy Yard, Boston, Mass., 10 July 1944, renamed Poseidon and reclassified ARL-12, 12 June 1944; launched 24 August 1944; sponsored by Mrs. Nora T. Twomey, and placed in reduced commission 22 September 1944.

Following initial commissioning, Poseidon steamed south to Baltimore where she decommissioned and completed conversion to a landing craft repair ship. Commissioned in full 13 February 1945, she completed shakedown in Chesapeake Bay and, assigned to ServRon 10, sailed for Ulithi, thence, in early June, to Okinawa. There, at Kerama Retto and at Buckner Bay, she repaired landing and patrol craft until the cessation of hostilities. Ordered back to the United States after World War II for inactivation, she decommissioned 30 November 1946 and was berthed with the Columbia River Group of the Pacific Reserve Fleet. She remained a unit of that group until struck from the Navy List 1 July 1961. She was sold 3 November 1961 to the Marine Power and Equipment Co., Seattle, Wash.