Short answers, pulled from the story.
Women wore heavy wool or flannel bathing gowns with long sleeves and skirts that dragged in the water. These garments included weights sewn into the hem to prevent the fabric from floating up and revealing the body.
Australian swimmer Annette Kellerman was arrested in Boston for indecent exposure because she wore a form-fitting one-piece suit that revealed her arms, legs, and neck. Her arrest sparked a national debate that eventually led to the adoption of the Annette Kellerman suit style.
French automobile engineer Louis Réard unveiled the bikini on the 5th of July 1946. He named the garment after the Bikini Atoll nuclear test that occurred four days earlier.
Austrian-born designer Rudi Gernreich introduced the monokini in 1964. The design consisted of a close-fitting bottom and two thin straps that formed a halter around the neck.
Swimsuits prior to the 1930s were typically made of wool which became heavy with water. Rayon, jersey, and silk were also used in the 1920s but proved problematic for durability when wet.
Blue, white, or gray swimsuits can be nearly invisible underwater making it difficult for lifeguards to spot drowning swimmers. Solid neon colors like neon pink or neon orange are highly visible underwater and have become a standard in competitive swimming and lifeguard training.