The main justification for pool cleaning is to prevent swimmers from contracting bacteria. However, accidents sometimes happen, so clothing was designed for swimmers who want to stay healthy. Except for the fact that they're composed of nylon and spandex rather than cotton or a polyester blend, crew tops are similar in appearance to any T-shirt or long-sleeved shirt. They are the ideal rash guard and serve the additional benefit of shielding the skin from the sun's UV radiation.