These videos have been posted before... they are worth a look if you haven't seen them. A few of the sequences from 1997 @50k to 71k are gnarly:
http://www.nps.gov/cany/river/highwater/video.htm
I wouldn't get in a raft on Cataract at that level unless the captain was a badass who knows how to bend the oars. There are some truly pathetic attempts at busting a move to avoid Satan's Gut in those videos. When I watch them I am saying to myself, "what in the fuck is that guy doing? can he even bench press the bar? he's going to kill everyone in his boat".