There's some interesting tidbits about the making of that movie beginning with the fact that Boorman, Director, and Dickey, Writer, disliked each other intensely and the actors all disliked Dickey. Boorman and Dickey would meet at night, and both were raging drunks, to discuss the scripts and shooting and finally it broke out into a fight and they ended up telling Dickey to take a walk. Ain't that peculiar? Two drunks that don't like each other decide to get together and get drunk and it ends up badly.
Ned Beatty damned near drowned because Boorman and Reynolds had demanded that they actually learn to ride the rough water. That scene where Ronnie Cox dislocated his shoulder was real, he can do that on demand from an earlier accident when he was younger.
One thing about that movie that didn't sit well with me, there were no normal people they encountered. My cannibal mutant sex with anything alarm would have been going off and I would have gone to White Water instead and I've been told I have a purdy mouth. When people that look like that behave like that, where's the shock value?