This is Cowley Steps on the river Exe just north of Exeter. We visited last week as part of a holiday in North Devon. This is where I finished the Exe Descent marathon race, somewhat prematurely, by breaking my paddles. Back in the late 1970's. The river was in high flood at the time and there was no way to avoid being rotated where the slope meets the wall and curls over... This is very low summer level. The race was after an overnight downpour.
I didn't leave the boat at that point but tried to push up off of the bottom to stay in to the race. That's probably when I snapped my paddle. I dropped over the next drop more or less sideways and got stuck in the stopper. A helpful frogman (provided by the race organisers!) lifted my bow out and pushed it downstream towards the last drop. That's the stopper I got stopped in, showing rather white.
At this point I realised one paddle blade was missing, by trying to use it for support. This proved to be time to swim over the last drop, under the bridge and drag the boat to the bank. No way to replace the paddle, so that was it.
I've heard, on T'internet, that Cowley Steps was designed by an engineer with a pathological hatred of all kayak paddlers.
Amen, brother. Amen!