Olivier Chromienne as seen on Behance.net
In the late 1910's bathing suits covered most of a persons body, particularly if that person was a woman. And she typically bundled her hair under a hat. By the 1940s gender integration combined with the downsizing of swimsuits eroticised municipal swimming pools. The modest swimsuits initially donned to dampen the sexual charge between men and women interacting in such intimate public spaces began to shrink and reveal more curves and skin. As a result swimming pools became erotic public spaces where scantily clad males and females displayed themselves and visually consumed others.
During the 1940s swim caps became scarce as rubber was needed for war materials. By the 1950s decorated caps come into vogue, and during the 1960s colorful flower petal swim caps became popular. Men's long hair styles of the late 1960s and early 70's made swimming pool operators change rules requiring swim caps for swimmers with long hair. Without swim cap requirements wearing swim caps fell out of fashion during the early 1970s. Competitive swimming in the 1980s and 1990s and the worldwide construction of indoor lap swimming pools for fitness swimming, made the swim cap popular again.