The U.S. Navy High Command conceived that "fleet submarines" were to complement the sluggish conventional battleships. With a high surface speed, heavy armament, and long operational range, they were supposed to conduct reconnaissance and finish off enemy ships once artillery duels between battleships ceased. However, after the attack on Pearl Harbor, their strategy changed, and a new type—Gato—was geared for extended patrols. Comfortable for their crews, these submarines carried a large fuel supply and torpedoes. USS Gato was laid down in October 1940 and commissioned in December 1941. The submarine conducted thirteen combat missions, earning the same number of battle stars and the Presidential Unit Citation.