Here's how you handle a situation like rounding a bend on a float trip and encountering someone that you feel has intentions of doing you harm. You just say "yo dude, Heads Up. what's with all the lawdogs upstream?" He/they say " WTF are you talkin' about", Then you say " F#@k I dunno, but I'm packin' a bag o weed so I need to get on downstream, later".
It's all about how you carry yourself. Works better than sitting there looking nervous and wondering if you should reach for your "equalizer". And yeah I've been there, talked my way out of a knife fight on the Niangua (see thread about area below tunnel).