In Stratford at lunch time, a couple of kayakers were hurling themselves repeatedly against the bottom of Lucy's Mill Weir. It looked like a fairly exhausting exercise to me, but they were clearly enjoying themselves, and R, who went to the kind of school at which you do this kind of stuff, said that they were practising paddling in turbulent water, and that this was such an obvious place to do it that he didn't know why people didn't do it all the time.
Strangely, it seems that they actually do do it all the time, because if you Google Lucy's Mill Weir, most of the first page of hits are pages about kayaking - but despite the number of times we've walked this stretch of the river it's the first time either of us has ever seen it happening.
I was very pleased with the way the BZ caught this action from over on the southern bank of the river - it would clearly be a very good sports photography lens, in the hands of someone with an interest in sport. That, however, would not be me.