A PBR-Patrol Boat River; that's the boat featured in the film
"Apocalypse Now." Part of the USN's Brown Water Navy during the
Viet War. About 300 of them were sent there, just over a hundred
Swift Boats were sent to Vietnam. The Swifts were 50 aluminum
riverine boats, the PBRs were about 32 feet long and all
fiberglass, using water jet engines (no propellers).