[FASTBOAT TOUGH]

This might help from the guys that rode them. Also any drawings or pictures can be clicked on and enlarged. Further bottom right pictures of ref 1 show PB MK III in additional weapons config. it appears in the drawings, they show the "standard" weapons config.
http://warboats.org/mk3.htm
https://nara.getarchive.net/media/a-...15ef?zoom=true
https://picryl.com/media/a-starboard...at-unit-e4105e

As of 2015 the PB MK VI is the "standard bearer" for the USN.
https://www.navy.mil/navydata/fact_d...&tid=2600&ct=4
https://www.naval-technology.com/pro...-patrol-boats/
https://www.bing.com/videos/search?q...4818&FORM=VIRE

Here's the main website for "warboats" above...
http://www.warboats.org/
http://www.warboats.org/vietnamboats.htm

In my current capacity I'm still qualified as a "Coxswain" on the 34-foot Dauntless Sea Ark Patrol Boats and for a short time a 40-ft Patrol Boat w/ twin Cummins turbo-charged diesel engines. That baby could "ride the waves" but she was a maintenance bear. We no longer "provide" those services and at times I miss it.

Regards,
Pat