Originally classified Agate (AM-78), Agate became PYc-4, 20 December 1940. She was built in 1930 by Mathis Yacht Building Co., Camden, New Jersey. as Armina (later renamed Stella Polaris) ; acquired by the Navy 27 October 1940; and commissioned 31 January 1941. Throughout most of World War II Agate was assigned to the 15th Naval District where she patrolled the Panama Canal. She departed the Panama Canal Zone 12 August 1944 en route to Philadelphia, Pennsylvania. There she was decommissioned 29 September 1944. She was turned over to the Maritime Commission for disposal 3 July 1945.