Snorkel

A curved tube that lets a diver or swimmer breathe at the surface while keeping the face in the water, saving tank gas before and after a dive.

A snorkel is the simple J-shaped tube that lets you breathe with your face down at the surface. For scuba divers its main value is gas economy and comfort: you can swim out to a descent point, wait on the surface in choppy water, or make a long surface return without draining your tank or lifting your head into waves every breath.

Modern snorkels add features to the basic tube: a splash guard on top to keep waves out, a purge valve at the bottom so a sharp exhale clears water easily, and dry-top designs with a float valve that seals the tube completely when submerged. Clearing a flooded snorkel with a single forceful blast is a basic skill taught in every open water and snorkeling course, and it is worth practicing until it happens without thought.

Opinions differ on wearing one during the dive itself. Many recreational agencies teach it clipped to the mask strap, while wreck, cave, and technical divers usually leave it off or stow a foldable one in a pocket because a dangling tube snags on lines and kelp. Pick the approach that fits your diving environment.