Wanted to let you know of an accident involving a submerged log at the bottom of the rapid named "ex-lax" on the east fork of the south fork of the salmon river downstream of Yellow Pine, ID.
We had a large group (~16 kayakers) that day. We scouted, but definitely fell into the large group heuristic trap of "follow-the-leader". Near the bottom of the rapid, 2 kayakers got stuck on the log momentarily, but eventually nudged their way over it. I came in after them, unaware of the log, and my bow went under the log. After water piled up on my stern and back for a few seconds, my whole body and boat were shoved under the log. This ripped my paddle out of my hands, forcing a swim. Luckily, the log was stripped clean and did not snag on any of my equipment.
From my perspective, there are two lessons here:
1) In large group settings, people need to speak up, especially while scouting. Apparently, one group member had seen the log during a scout, but failed to make it clear to everyone that it was there.
2) In large group settings, keep good spacing and read the water for yourself! As one of our group members put it, "It was like lemmings over a cliff, except the cliff was a log".
...I guess large groups just suck.
I've included two pictures on this email. While you can see the log from downstream, it is completely invisible from the upstream view.
One of the boaters that got pinned, Micah Kneidl, had a GoPro on. He has posted the video on his personal facebook page.
Please let me know if you need any more information, and thank you for helping keep the boating community safe!
P.S. This same info went out on the Boise kayaking email list serve, and was heavily debated in a thread. If you would like to be added to this group, please let me know.