A snorkel is a device that allows a person to breathe while swimming underwater. It typically consists of a curved tube that extends above the water's surface, enabling the swimmer to inhale air without having to surface. Snorkels are commonly used in activities like snorkeling, where individuals explore shallow waters and observe marine life. Snorkels are often paired with a mask that covers the eyes and nose, providing a clear view of the underwater environment. Some snorkels also feature a valve system to prevent water from entering the tube, making it easier for users to breathe comfortably while enjoying their aquatic adventures.