Just noticed this thread (slow day here at work). I make posts on the Nude Sleeper's forum, usually contrary to the party line (that is, Nat's posts). My experiences were quite different from his.
I grew up in a small town. There was no YMCA. In fact, I now live in a county with over a million in population--with one YMCA. I've never set foot in a Y. So, to say that all boys used to swim nude at the YMCA in years past is a stretch of the imagination. Not because boys (and men) did not swim nude there, but simply because not everyone belonged to the Y. They didn't all have swimming pools anyway.
Another frequent topic is swimming nude in high school. Nat never did, yet he never stops talking about it. This same county where I live has no high school with a pool. I did, however, swim nude in a certain college pool. There's no question about that, either. It's just that I find it amazing that a high school would have a pool. But we did take showers after gym in junior high and high school. And then there was the army, too.
I was an only child. My best friend was an only child. Another friend had two older sisters, no brothers. His next door neighbor was an only child. I've never understood why it was called a baby boom. My father was one of thirteen. True, we only had one bathroom in a house that was bigger than the one I live in now but a weekly bath was sufficient. My parents, however, were privileged enough to have their own room, so I never saw them naked.
And finally, there was no boy's club back home.
We moved to the country when I was still in high school. I don't know where I'd heard about skinny-dipping but I had visions of that being a common practice. It wasn't. What was lacking was the old swimming hole. Never heard anyone talking about swimming in the old swimming hole. This was back up in the hills, you understand. There used to be a mill near where we moved but the only thing remaining was traces of the dam that created the mill pond, which might have been a good place for swimming. I can only relate my own experiences and that's what they were. Nat keeps saying that I lived an atypical life and everyone else was different. Could be.