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 Commonwealth of the Philippines.

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.

11 as follows: "The Off-Shore Patrol shall comprise all marine equipment and personnel acquired by the Philippine Government and assigned either in peace or war to the control of the Chief of Staff (PA).

It shall have such duties and powers as may be described by the Chief of Staff, PA."[1]This act called for the creation, by 1946, of a force of thirty-six fast torpedo boats (PT) as part of the Philippine Army.

In June 1938, he was relieved by Captain Jose V. Andrada, a United States Naval Academy graduate (Class of 1930), who originally assisted Ramos but was determined to be better qualified.

They were all trained on seamanship, navigation and gunnery in sessions that were conducted with the USNA graduates as instructors at OSP headquarters in Muelle del Codo, Port Area, Manila.

[7] US Military Advisor to the Commonwealth of the Philippines General Douglas MacArthur states, "A small fleet of such vessels will have distinct effect in compelling any hostile force to approach cautiously.