4m 9sLength

Patrol Boat, River (also referred to as Riverine and Pibber), or PBR, is the US Navy designation for a type of rigid-hulled patrol boat used in the Vietnam War from March 1966 until the end of 1971. They were deployed in a force that grew to 250 boats, the most common craft in the River Patrol Force, Task Force 116, and were used to stop and search river traffic in areas such as the Mekong Delta, the Rung Sat Special Zone, the Saigon River and in I Corps, in the area assigned to Task Force Clearwater, in an attempt to disrupt weapons shipments. In this role they frequently became involved in firefights with enemy soldiers on boats and on the shore. PBR's were also used to infiltrate Navy SEAL teams. The PBR was a versatile boat with a fiberglass hull and water jet drive which enabled it to operate in shallow, weed-choked rivers. It drew only two feet of water fully loaded. The drives could be pivoted to reverse direction, turn the boat in its own length, or come to a stop from full speed in a few boat lengths. The PBR was manufactured in two versions, the first with 31 foot length and 10 foot, 7 inch beam. The Mark II version 32 feet (9.8 m) long and one foot wider beam, had improved drives to reduce fouling, and aluminum gunwales to resist wear. It usually operated with four enlisted men, of which the most senior crewman was designated the boat commander. Often, however, a junior officer would be assigned as boat commander. The boats were powered by dual 220 hp (164 kW) Detroit Diesel engines with Jacuzzi Brothers water jet drives. The boats reached top speeds of 28.5 knots (53 km/h). The boat was typically armed with twin M2HB .50 caliber (12.7 mm) machine guns (the forward '50s), as well as a rear M2HB, an M60 7.62 mm machine gun, a Mark 19 grenade launcher, and sometimes a 20 mm cannon. The machine gunners and conning tower were protected with ceramic armor.