For some reason [maybe their very wet operating conditions] the PBR/Alpha Boat/Monitor crews were always after replacement generators. And, of course, booze. No worries!
Dual .50s were the rig of choice....
The over-and under setup with the .50 M2 over a direct-firing 81mm mortar was also very highly thought of, a great idea the Navy swiped from the Coast Guard. Anything a .50 couldn't shoot through [like an overhanging river bank] one of the 81mm rounds could generally either bring down entirely, or pepper with an airburst. And at night, they could through out LOTS more illumination than a couple of popflares.
The Navy guys were also impressed when a couple of tank crews were sent out with 'em on TDY to try out the gun mounts with tanker's M85 .50 caliber guns instead of their twin M2 HBTT's in the gun tubs. The M85 used a different, M60-type link, which gave it a selective rate of fire, either the *usual* 550-600 rounds per minute of the M2, or a *fastfire* accelerated rate of 1100 RPM, [known as *Chinese Overdrive*] almost 20 rounds per second, times two guns, about 35 shots per second from their 2-gun sidebyside setup. Used with a starlight scope, they were just the ticket for what the other people thought was a night ambush.
The Marines also used the things in the cupola of their LVTs, and there was a tripod and backplate assembly designed for ground use, not needed in the gun tub on the river boats. I always wanted to try an M16 quad .50 mount with four of the M85s on fastfire, but the chance never came along. And you needed to use cut-open 5-gallon gas/water cans for ammo cans- the GI 105-round ammo can went empty in five or six seconds. Later we got the 3000-round ammo boxes for minigun ammo, and they were reworked for .50 ammo.
