I can remember back when I was 10yr old, when a boy from our school drowned swimming near the bridge supports in the river Thames, it was was popular then for us kids to go swimming in the river, especially during the summer holidays, but most did it a long way from the bridge.
At Morning School assembly, we got a very strong lecture on what had happened and why, that year our school built a small swimming pool, maybe only about 5meters wide and 20meters max long, then we all had swimming lessons (games) it was bloody freezing, but we got on and done it, I remember the teacher got the whole class to walk around in the water in one direction until we had created a current, then she blew the whistle and we had to change direction against the current, although I could already swim, it was a very important lesson learnt. The pool was open for us to use in the summer holidays, we had no local swimming pool at that time. Oh and I was the first one ever to swim the length of it underwater, and mentioned in assembly. I taught myself to swim on our 2 week holiday every year while mum and dad slept in deckchairs, I was the only one in our family out of 5 able to swim. (and drive when I got older)