The PGM-39 class Patrol Gunboat, Motor were a class of fifty nine gunboats constructed in various shipyards for the United States Navy from 1959-1970. The design was based on the United States Coast Guard Cape class patrol boat cutter design with a five foot hull extension. It was specifically designed for the U.S. Military Assistance Program and was used by the Philippine, Indonesia, South Vietnam, Thailand, Burma, Ethiopia, and Ecuador navies. The PGM-39 class has varied weapons mix of 40mm and 20mm cannons, 12.7mm machine guns, and 81mm mortar.