At Crossfields, an all boys public school, swimming lessons involved compulsory nudity.
I wish this wasn't true! The practice ended just after I left, due to the 'self-consciousness of the boys'. No shit. This was in 1985.
A nice twist came when the swimming teacher's daughters (in cossies) were in the pool on some sort of open day thing, and we all dived in to join them, much to their embarrassment, but not ours.

It was only reading the previous story that it struck me as odd that at my primary school swimming pool, the boys changing rooms had one wall which consisted of a huge, sliding patio-type window. Facing onto the school field. And swimming lessons used to regularly run over into breaktime, when, of course, the whole school was allowed, en masse, onto the playing field. Which, to add insult to injury, was bordered all round by houses.
To this day i cannot think of one possible reason as to why changing rooms in a swimming pool would be required to be glass-sided, aside from the obvious solution that perverts were involved at every level of the design process.
There were also 'helpers', one of whom was my grandfather. Part of the 'helping' remit was to ensure that boys got changed properly and promptly. So any boys resisting the public change would be virtually wrestled into the room, and forcibly dressed in front of the school, and town, by my grandad. Most opted for the easier path.

I was a pupil in the early 1980's at cros(s?)fields school in Reading. I was particularly disturbed by the practices of naked swimming at the school. We were made to strip off, sit on the benches that ran alongside the pool, everyone made to stand up, turn round and each to lift up our feet for the instructor to walk along the line to "check for verrucas" it's only now that I realise what they may have been doing...This happened every time. There would also be activities where we would have to regularly get out of the pool.
Also, some teachers would swim in the pool, naked... The pool at the time also had big glass windows which faced out onto the playing fields.....
During showering after games and swimming the teachers would watch to "make sure we showered" and also watch in the communal shower....
I vividly remember this and the feeling it gave me being one of shame and that this was wrong. I couldn't tell my parents because of this.... My parents even made sure I had my swimming trunks which I would wet to make it look like they were used...
If this was all ok and acceptable why when I was at swimming galas were we all wearing costumes?. When parents were watching....
This has been on my mind all these years .. If anyone else has any more information please post on here and I will contact you.