A swim cap is a durable latex, silicone, or lycra head cover that is worn for practice sessions and competitions while swimming.
It shields hair from the chlorine in the water and lowers drag, allowing swimmers to swim faster. Triathletes and some swimmers also use colorful caps so they can be noticed when in open water. Caps also secure goggles. Most prefer silicone caps as they are durable and comfortable, whereas latex caps are thinner as well as permeable. Caps may be used in races for safety as well as to distinguish swimmers.