Snorkeling is the practice of swimming at the surface of a body of water while equipped with a diving mask, a shaped tube called a snorkel, and usually swimfins. Combining these tools allows the snorkeler to observe underwater attractions for extended periods of time with relatively little effort. The primary attraction of snorkeling is the opportunity to observe underwater life in a natural setting. This may include coral reefs and their denizens, such as fish, cephalopods, starfish, sea urchins and mollusks. Snorkeling in sandy areas may allow sighting ofrays and various flatfish. Other organisms that can be seen while snorkeling include various forms of seaweed,jellyfish, shrimp, sea turtles, and occasionally anything else which may be found in the ocean. Many of the organisms found in reef locations are vibrantly colored and very abundant, making for an engrossing experience.