Most high-performance swim caps are made from silicone or latex, which are both soft and offer good elasticity. They can effectively cover the entire head while reducing water resistance. In competitions, athletes often choose bright colors to increase visibility. Some swim caps are also designed with air vents to ensure comfort on the head.

Although swim caps may seem simple, their role in competition cannot be overlooked. A suitable swim cap not only reduces water resistance but also provides a psychological edge—by keeping hair from floating in the water, it allows athletes to focus more on the race.
For some athletes, a too-tight swim cap can cause discomfort or a feeling of pressure on the head. Particularly for those competing in long-duration events, wearing a swim cap for extended periods may lead to scalp irritation or a lack of breathability.