Water tube

A tube

— a snorkel is a device that allows you to breathe with your face in the water. At one end of the tube is a mouthpiece, which the diver clamps in his mouth, and the other end, when swimming face down, protrudes from the water, so that air can be inhaled and exhaled through the tube. Some models are equipped with a special float valve that, when fully submerged, closes the tube and does not allow water to enter it — this eliminates the need to “blow through” the tube after diving to depth.