Was out in Cali a few weeks ago. Did not boat it but hung out at South Silver one day, mainly at Skyscraper. Probably watched about two dozen boaters or more run that drop + Off-Ramp. No trouble except one guy got bounced off line in the middle of the drop (went a couple of feet right of boater in this photo), stuck in that pothole, surfed, flipped, multi roll attempts, finally swam, down time in the aereated water, then washed into next part and pinned face forward. I'm guessing he was 40-45 seconds in and best I could tell, only had one decent breath before he washed out of the pothole.
I was standing directly over him about 20' up with nothing but a camera w/ a dead battery. I could hardly see the top of his helmet while he was pinnedm assumed foot entrapment, and figured that was the end. Lots of folks all around, but no one really in position to help much, myself included. Bad, bad feeling. One throw rope nailed him on the top of his head, but there was no hand to grab it.
Turns out, he was pinched at the hips between rock, lots of pressure against his back, but was able to prop up on his elbows, grabbing short breaths in an air pocket. After 2-3 "quarter-breaths" as he called them, he was able to lift himself up and out of the pinch with his elbows/shoulders. Went over the bottom tier of the drop looking like a rag doll (I figured he was unconscious), but he started swimming left, grabbed a rope, and to everyone's amazement and relief, seemed to be pretty much fully recovered in 20 mins or so.
He said afterward that his raft guiding experience - in the water, coming up under/between/around rafts, played a huge factor and helped him to stay calm, and to will himself not to try to suck air when there was only water to breathe.
So Moral 1: Don't assume and never give up! I assumed foot entrapment, which is frequently fatal. I assumed he was getting no air. The drop was highly aereated, and he was face forward, both very much in his favor. Finally, didn't know how he could wash out, but assumed he was unconscious, and was about to wash over Off-Ramp.
Moral 2: Staying calm and keeping your wits about you is huge. Pretty sure I would not have been able to do as well as he did in that situation. As stated above, best way, if not only way to do this, is practice, practice, practice. Along these lines, Doug Ammons has an outstanding article in the current issue of AWA Journal. Find it; read it. Maybe the best single article on boating I've ever read.
Moral 3: Occurred to me later that some Class V/V+ runs are being run so routinely these days (South Silver, Green, etc.), we may be taking a more casual attitude about setting safety on these drops/runs. Most of us that Sunday afternoon were enjoying the show - great entertainment watching folks, for the most part, clean an awesome pair of drops. Certainly all of the boaters were all business when they were running that drop, but no one was set up or positioned for effective safety/rescue.
As they say, experience is what you get when you get what you don't want. Happy ending on this one, but good lessons re/learned.