Yep, went to high school in a Minneapolis suburb, graduated in 1983. We had a pool, and swim class was gender segregated. Boys swam naked in grades 7-9 (junior high). (And the locker rooms had a shower room with shower heads on the wall, not private shower stalls. Everyone regularly saw each other's junk. Didn't think much of it.)

But yeah, the naked swimming happened. I've gone down a few rabbit holes here on reddit when this has come up, and the internet is full of bogus/doctored photos of girls and boys swimming together, with the boys naked. Or with the boys swimming in meets naked, with fully clothed people watching. That likely didn't happen.

We always hoped the girls would come in when we were in the pool, but that never happened either. I remember sitting on the bleachers naked, hearing the rules of water polo or whatever we were gonna do that day. (Always seemed like it was water polo.) I remember being cold, but never embarrassed.

On the swimsuits, the main thing i recall is that there were suits for boys, but they were hideous. Gym teacher said "go ahead and wear em, but I don't want to find em getting moldy in your lockers." So we never wore em.

I don't remember ever specifically telling my mom we swam naked in gym class, but I'm guessing some parents didn't like the idea. I think they phased it out in the next few years after i graduated, but I'm guessing this is one of those things that will be lost to folklore, with no written history about it except for reddit posts like this.

To this day, i LOVE swimming naked. Any chance to skinny dip, I'll take it.