PTF boat, (short for Patrol Torpedo, Fast) are fast United States Navy patrol boats introduced in the early part of the Vietnam War. The PTF designation was give to 26 boats with four different boat designs. The PTF boats were the Vietnam War "brown water" river boats version of the World War II PT boats. They were heavily armed gunboats that were used by the US Navy and by Special forces. The first two PTF boats were commissioned 21 December 1962. The last two PTF were commissioned on 8 April 1968. PFT boats were replaced by the new Patrol Craft Fast (PCF) boats that were more widely used in Vietnam. There are five PTF boats that have survived and are in various state of restoration. The "Torpedo Boat, Fast" designation is a hold over from World War II, as PTF boats were not equipped with torpedoes, as they were mostly used in shallow river waters.