Capt Willard went hunting Col Kurtz in Cambodia on a PBR in "Apocalypse Now."
I thought I recognized that boat captain in the movie! It was Big John!
There were Coast Guard PBRs in An Thoi; now that I recall, a PBR was the first boat I was on in Nam...flew in to the airbase in An Thoi, and was transported by PBR south to the base at the southern tip of Phu Quoc island.
Our boat went aground once and a PBR pulled us off a sand bar...OH the mortification, a Navy boat pulled free by the Coasties.