Revisiting my ongoing study of nudity in America… as well as my recent post on “Swimming Nude Was the Norm 30 Years Ago” –

An early casualty of gender equity was males-only nude swimming in YMCA pools, middle schools and high schools all over the country. Men and boys had been accustomed to swimming au naturel at the YMCA in Ys everywhere, since the 1890s. The practice may have evolved from problems created by the long, wool swimming suits then in fashion, which apparently shed so much they gummed up the pool filters. Later, nude swimming was justified on the grounds of hygiene. A handbook in use at the Ys in the 1920s required that “A good soap bath must be taken before entering the swimming pool” in the same paragraph that specified “The wearing of swimming suits or supporters will not be allowed except by permission from the director” (Information for Members).
In any case, the custom was phased out as co-ed swimming became more common, although pools continued to be reserved for men from noon to 2 p.m. daily until the mid to late 70s. Cases like that of Sonstelie -– a newcomer to the Seattle YMCA who wanted to swim during her lunch hour –- fired off a letter asking how an organization supported by the United Way could maintain such a discriminatory policy. “They changed immediately,” she says. “I had never seen an organization move that quickly” (Sonstelie Interview).
The new policy led to what Dick Knapp, the Downtown YMCA’s physical director in the early 1970s, called “interesting times,” since many of the men who regularly used the pool at noon had never had to wear swim suits before. When the gender barriers fell, it took a while for all the men to get used to the new rules.
