The Offshore Patrol (OSP), also known as the Mosquito Fleet was a small naval branch of the United States Army, intended for inshore defense of the Philippines. It was active from February 9, 1939 to June 30, 1946. The OSP became part of the United States Army Forces in the Far East (USAFFE) on July 26, 1941, with General Douglas MacArthur as Commander. During the Japanese invasion of the Philippines, the Patrol engaged in limited naval operations along the coastlines of Bataan and Corregidor, against the tight enemy blockade, to bring much-needed provisions to the beleaguered Filipino and American troops during the battle. Undaunted by enemy superiority, the ubiquitous patrol boats fought with zeal, courage and heroism, hitting Japanese warships with torpedoes when given the opportunity. The unit relied on speed and surprise to attack larger vessels at close range.