Patrol Boat, River (PBR) - Brown Water Navy

The versatility​ of this boat is namely due to its​ minimal draft, 2 feet, and it's high speed roughly 28kns. The boats could go from full speed to full stop in just a few boat​ lengths, it could also turn in its​ own length. The fiberglass hull, jet drive propulsion​ was revolutionary​ in the marsh weed-filled​ canals​.

The enlisted crew typically consisted of 4, led by a first class petty officer. Enginemen​, gunners mate​, ​and seaman made up the crew each would train on each others position.

Official Armament:
1 × twin M2HB .50 caliber (12.7 mm) machine guns (forward in a rotating tub)
1 × single M2HB (rear)
1 or 2 × M60 7.62 mm machine gun(s) (side-mounted)
1 × 40 mm Mk 19 grenade launcher

PBR crews were known for altering their boats adding piggybacking features to traditional specifications.

These modifications would include MK18 piggyback M2HB 50 cal.

Similar to the larger Patrol Craft - Fast (PCF) piggyback 81mm and 50 cal arrangement shown below.

PBR Mark II forward .50 caliber M2 machine guns

The Mark II was lightly armored, relying on speed and maneuverability​ in tight waterways to get out of tight situations. The .50 cal machine guns had some ceramic armor shielding and the Coxswain's flat had some quarter inch thick steel armor plate,

The MkII proved itself to its crews. The iconic image of green sailors would not be lost after the war as the craft would carry on for decades.

After the Vietnam War, the United States active duty moved away from the riverine operations and the MK II PBR was handed to reserve forces to primarily​ operate out of Marine Island. The riverine training facilities operated out of the base until 1995 using the marshlands​ along the Napa River. The area is now a state nature preserve and wetland but still permits riverine training operations which now primarely takes place in the Sacremento area.