During the 1920s and 1930s, people began to shift from “taking in the water” to “taking in the sun”, at bathhouses and spas, and swimsuit designs shifted from functional considerations to incorporate more decorative features. Rayon was used in the 1920s in the manufacture of tight-fitting swimsuits, but its durability, especially when wet, proved problematic, with jersey and silk also sometimes being used.
11 women and a little girl lined up for bathing beauty contest, USA Source
Bill Norton the bathing beach policeman measuring distance between knee and bathing suit on woman, Washington, D.C. Source
Contestants, Bathing Girl Revue, Galveston, Tex., May 13, 1923 Source
Contestants, Bathing Girl Revue, Galveston, Tex., May 14th, 1922 Source
Errnest and Pauline Hemingway, San Sebastian, circa September 1927. Photograph in the Ernest Hemingway Photograph Collection, John F. Kennedy Presidential Library and Museum, Boston. Source
French antique dealer Yvonne de Bremond d’Ars (1894-1973) on the beach at Deauville.Source
High diver Beatrice Kyle sitting on a fire engine wheel between acts at the Society Circus at Fort Myer, Va.; for the benefit of the Army Relief Fund; Apr. 25, 1924. . source
Human tower on the sands at South Stradbroke Island, 1922 Young people from Roe’s Camp playing games on the beach. . source
Mack Sennett’s Bathing Beauties . source
Burlesque and vaudeville performers wore two-piece outfits in the 1920s. The 1929 film Man with a Movie Camera shows Russian women wearing early two-piece swimsuits which expose their midriff, and a few who are topless. Films of holidaymakers in Germany in the 1930s show women wearing two-piece suits, In 1928, Speedo introduced their racerback silk suit that was optimized to fit the body shape.
1920s swimsuit postcard . source
Women dancing on beach, Toronto, Canada. . source
Woman on beach in Bermuda, with seaweed, 1929 . source
woman in a bathing suit is walking a leashed seal on the beach in Long Beach as people watch. . source
Viola Swinnerton & Anna Neibel . source
Truus van Aalten (Dutch film actress, 1910-1999) meets a fake frog. . source
Annual_beauty_show,_Washington_Bathing_Beach . source
Man Swimsuit, 1920; Germanic National Museum in Nuremberg . source
Argentine swimmer Alberto Zorrilla in 1925. source
Bathing models in a museum, 1920.source
Bath costume contest,1921, Source
By the 1930s men began to go without shirts for swimming, and bare-chestedness in male swimwear became the norm by the end of the 1940s, including in competitive swimming events. The norm of male bare-chestedness in swimwear did not extend to other competitive sports.