Speed 18 k
Armament 1 5"
Castle Rock (AVP-35) was launched 11 March 1944 by Lake Washington Shipyards, Houghton, Wash.; sponsored by Mrs. R. W. Cooper, and commissioned 8 October 1944, Commander G. S. James Jr., in command.
Castle Rock stood out of San Diego 18 December 1944 bound for Pearl Harbor and Eniwetok, where she arrived 28 January. Assigned to escort convoys between Saipan, Guam, and Ulithi until 20 March, Castle Rock then took up duties of designed mission, tending sea lanes at Saipan. In addition to providing the essential home base for seaplanes as they carried out varied air operations including reconnaissance, search, and hunter-killer activities, Castle Rock herself performed local escort duties.
On 28 November 1944, Castle Rock sailed from Saipan for Guam, where she embarked a group assigned to study Japanese defenses on Chichi Jima and Truk. This key to future operations continued until 5 January, when Castle Rock returned to tender operations at Saipan
Castle Rock left Saipan astern 9 March 1946, sailing for San Francisco where she arrived 27 March. Here she was decommissioned 6 August 1946, and loaned to the Coast Guard 16 September 1948.