Riverine Was the Forgotten Hero of the Vietnam War
BY MATT CRISARA
To most of you, PBR probably sounds like a mid-strength beer you’d find stashed in a frat house fridge. But I’m not talking about Pabst Blue Ribbon here. Instead, this PBR—the Patrol Boat Riverine—was one of the most important fighting vessels that played a key role in protecting U.S. troops during the Vietnam War.
As the conflict escalated in the 1960s, the U.S. military realized the need for a relatively small yet nimble craft that could navigate the shallow rivers of Southeast Asia. So they reached out to Hatteras—a manufacturer of luxury yachts based out of New Bern, North Carolina—to build a prototype.
Instead of executing an entirely new design, Hatteras chopped down its existing 41-foot-long fiberglass family cruiser into a 31-foot fighting machine. A working prototype of the Patrol Boat Riverine was ready to go in just six days—very impressive, given the expansive list of modifications. Along with making the boat much shorter (and wider) than before, Hatteras moved the engines farther forward. The propellers were swapped for jets, which served to improve ground clearance and preclude the problem of props getting snagged. All of these alterations made the boat ideal for supporting troops from the shallow waterways flanking the Mekong River.
The jet propulsion system wasn’t exactly what you’d find in an F-4 Phantom II fighter plane. Believe it or not, it was manufactured by Jacuzzi. The PBR had a series of intakes underneath the hull, protected by thin mesh, to feed water to an impeller. The impeller then forced the water through stage two at incredibly high speed before shooting it out of a nozzle in the rear of the boat.
In the case of navigating shallow water, this jet propulsion is far superior to traditional propellers, with less risk of grounding out. Why? Because the only obstructions coming out the back of a jet boat are the nozzles themselves; this gives them much better ground clearance.