PT boats were a torpedo-armed fast attack crafts used by the United States Navy, during the Second World War, especially in South Pacific war theatre. The acronym PT stands for “Patrol Torpedo” and immediately identify the operational use : to carry out patrol and attack, with her torpedoes against surface targets, duties. The Elco Naval Division, located in Bayonne, New Jersey, was the most famous manufacture of PT boats during the World War II. The famous PT-109, belonged to the ELCO PT-103 class, had a length of 80 feet (24 m.) and a full load displacement of 56 tons. Powered by three 12-cylinders 1,500 horsepower Packard gasoline engines, was able to reach the speed of 41 knots. The primary offensive armament was based on four 21-inch (53 cm.) torpedoes. On April 1943, the command of PT-109 was taken by Lieutenant Junior Grade John itzgerald Kennedy, the future President of the United States.