Is true than in 50's thru 70's pt class in US ( specially swim class) was naked ?

Nudistische Schulerziehung

Read here...u must translation

 

I can't say anything about swim class at school, because my school didn't have a pool or swim classes. But yes, the YMCA's used to have nude swimming back in the day, However, by the time I was a kid that seemed to have gone away, as all of the Y's were coed by then.

 

I grew up in East Germany, back when it was still the GDR. In some schools, it was common to conduct swimming lessons naked. I was in first grade at a very large school with a big indoor swimming pool, and we started learning to swim naked there.

In many schools, swimming lessons were taught naked for the first three years of school.

At my school, it continued until the end of sixth grade, until I was 13 years old.

 

Are there any YMCA's that do nude swimming anymore?

 

There have been many discussions of this in recent years. The short version is yes, it was widespread and normal in much of the U.S. and Europe in the early- and mid- 20th Century. Unfortunately, many "accounts" and photographic "evidence" are pure fiction. I'm not good at attaching links, but "Google" these two items, Historic Archives Nude Male Swimming and Historical Nude Male Swimming Images, and you'll find high quality, "scholarly" treatment of the subject. The second one is particularly enlightening because the author reveals (no pun intended) many if not most of the period/vintage photos of young men/boys and young women/girls participating in "CFNM" swimming competitions as doctored frauds. This author is computer-savvy enough to mine the "meta data" for the truth therein.
FWIW, the meta data don't lie. Some years ago a man ran for president of a country whose constitution required that the president be a natural born citizen. While there should be no stigma to having been raised by a "single mom", there was some uncertainty surrounding the candidate's early life and paternity. Once again, in and of itself, the 1960's hit song "Love Child" notwithstanding, not a negative reflection on the candidate. But be that as it may, a birth certificate was not produced until after the candidate was elected and assumed the office of president of that country. And subsequent analysis of the "document" revealed it to be a digital cut-and-paste. And, somewhat coincidentally, birth records from the year in question were removed or destroyed in not one but two countries... "Go figure". It has even been suggested that the fact that the meta data that were not "scrubbed" from the so-called birth certificate was in effect a digital "middle finger" to those who were concerned about the elusive "eligibility" of the candidate...
FWIW, while I had swimming lessons in the early 60's and was on a high school swim team in 1971-72, we all wore suits. The swimming lessons were at an outdoor municipal pool only in summer, and the high school added the new pool in time for my senior year. So no "tradition" of no suits for guys...
The two sites I have referred to unequivocally attest to the widespread acceptance of "swimsuit optionality" for boys for a very long time. Just be wary of the photographic "evidence".