The Offshore Patrol was a rudimentary navy

Navy

A navy is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake- or ocean-borne combat operations and related functions...

, intended for inshore defenses only, called for by the Philippine National Assembly in its National Defense Act of 1935

National Defense Act of 1935

The National Defense Act of 1935 was passed by the Philippine National Assembly on December 21, 1935. The purpose of this act was to create an independent Philippine Army, this was interrupted by World War II.-Provisions:...

. This act called for the creation, by 1946, of a force of 36 torpedo boat

Torpedo boat

A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

s (PT) which were to be built and designed by British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 shipbuilders.

Two of the boats had been delivered by 1939, when the war in Europe began. By October 1941, a third boat had been assembled in the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

. Apparently there were eventually five boats built, and attached to USAFFE, although they are not always listed in strength and composition tables.

On December 4, 1941 Enrique L. “Henry” Jurado (1911-1944), U.S. Naval Academy

United States Naval Academy

The United States Naval Academy is a four-year coeducational federal service academy located in Annapolis, Maryland, United States...

 graduate (Class of ’34) became the officer-in-command of the OSP, right at the start of the WWII.

Torpedo boats of the Offshore Patrol

These boats were based at Cavite Naval Base, Luzon

Luzon

Luzon is the largest island in the Philippines. It is located in the northernmost region of the archipelago, and is also the name for one of the three primary island groups in the country centered on the Island of Luzon...

• PT Q-111 Luzon
  • Major E. Jurado
• PT Q-112 Abra
  • Lieutenant R. Alcaraz
• PT Q-113 Agusan
  • Lieutenant S. Nuval
• PT Q-114 Danday
  • Lieutenant A. Campo
• PT Q-115 ?
  • Lieutenant C. Albert

The Off Shore Patrol craft were berthed at "Muele del Codo" Engineer Island in Manila's Port Area. During the Bataan Campaign they operated out of Sisiman bay. The US PT boats of Lt. Bulkeley were also in the same bay but alongside a tender:

• Motor Torpedo Boat Squadron Three
  Motor Torpedo Boat Squadron Three
  Motor Torpedo Boat Squadron Three was a United States Navy squadron based at Cavite, Philippines, from September 1941 to mid-April 1942. It was commanded by then-Lieutenant John D. Bulkeley and made up of six motor torpedo boats: PT 31, PT 32, PT 33, PT 34, PT 35, and PT 41, the last as the...
  
  
• PT 41
  PT 41
  Motor Torpedo Boat PT-41 was a PT-20 Class Patrol torpedo boat, built at Elco and commissioned on 23 July 1941.PT-41 served as the flagship of Motor Torpedo Boat Squadron Three, which was based in the Philippines from late 1941 to April 1942. The commander of PT-41 was Lieutenant John D....
  
  

Offshore patrol torpedo boat designs

The PT-boats of the Offshore Patrol were to be 65 ft (19.8 m), with a 13 feet (4 m) beam. They were to have three 12-cylinder engine

Engine

An engine or motor is a machine designed to convert energy into useful mechanical motion. Heat engines, including internal combustion engines and external combustion engines burn a fuel to create heat which is then used to create motion...

s, and a speed of 41 knots (22.3 m/s). Their armament was to consist of two torpedo

Torpedo

The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

 tubes, depth charge

Depth charge

A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...

s, and light antiaircraft guns.

US Military Advisor to the Commonwealth of the Philippines

Commonwealth of the Philippines

The Commonwealth of the Philippines was a designation of the Philippines from 1935 to 1946 when the country was a commonwealth of the United States. The Commonwealth was created by the Tydings-McDuffie Act, which was passed by the U.S. Congress in 1934. When Manuel L...

 General MacArthur

Douglas MacArthur

General of the Army Douglas MacArthur was an American general and field marshal of the Philippine Army. He was a Chief of Staff of the United States Army during the 1930s and played a prominent role in the Pacific theater during World War II. He received the Medal of Honor for his service in the...

states, "A small fleet of such vessels will have distinct effect in compelling any hostile force to approach cautiously."