Bath costume with high water slipping properties

A woman's bath costume having a high water sliding property, comprising a bath costume body, made of a resilient material adapted to perfectly adhere to a body of said woman and provided with an outer smooth surface to reduce to a minimum a water slipping resistance thereof, wherein said bath costume body is completely made of a waterproof material and is adapted, as it is worn by said woman, to tightly encompass an upper portion of a trunk of said woman to approximately midway up on the neck of said women, and said costume having an outer edge of the upper portion at shoulder position which ends approximately at the juncture of arm and torso.