honestsweat saidAsk your YMCA to engage in some retro action and return to the 1950s when they didn't allow men to wear bathing suits. (Unhygienic!) Problem solved.
YMCAs became coed "Family Centers" to stay afloat financially in the late 1970s, and also under pressure from feminist groups. Therefore nude male swimming had to end.
And it wasn't so much that men weren't ALLOWED to wear swimsuits, but rather that they weren't needed. I used Ys from the 1950s, I know.
Men were naked together in a gang shower before you entered the pool, and naked again when you showered afterwards. There were no women in the pool area.
The showers of some Ys I used (and a few Army athletic centers) were wide open to view from the pool area, no doors or partitions. Since it was a male-only environment no money was wasted on superfluous and inconvenient privacy doors. You all showered together nude, you swam together nude. It made perfect sense to us at the time.
Why exactly would you need to put on a swimsuit to get it wet in the pool? Modesty? It was considered unmanly to be shy among other naked men in that time period. Only girlie "queers" might have a problem with it, was the common assumption.
Wearing a suit of natural fabric could produce lint that clogged the early pool filters. Or was dirty and full of mildew, from being kept wet in a gym bag or locker. So there was a practical, hygienic side to it, too.
Years later, when I had to conduct Army drownproofing classes in a college pool, I consulted some books on swimming instruction and pool management. And these books actually advised that males should swim naked in the absence of females. Although they did say boys and men should swim separately at segregated times. But I also saw this guidance regarding boys not applied during periodic "Father & Son" days at the Y.
But the main fact remains: It wasn't that we HAD to swim naked, but rather that we DIDN'T HAVE to be bothered with an unnecessary swimsuit. And most guys liked it that way. That's the point lost today from the perspective of the new male modesty, that we didn't have back then.