TUSA Sport Adult Imprex Snorkeling Combo with Reusable Bag. $ Limited Stock! Cressi Air Crystal Scuba Mask. $ Limited Stock! TUSA Sport Adult Liberator Snorkeling Combo with Reusable Bag. $ Limited Stock! Aqua Lung Sport Adult Saturn Snorkel Mask. $ TUSA Sport Adult Splendive Snorkeling Set. The snorkel itself is a J-shaped tube with a fitted mouthpiece for breathing. Flippers, also called fins, are shaped like elongated duck feet. They slip over the feet, allowing you to swim much faster and further, and with less exertion, than you would swim with bare feet. You’ll find snorkel sets in sizes for both children and adults.