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. In cooler waters, a wetsuit may also be worn. Combining these tools allows the snorkeler to observe underwater attractions for extended periods of time with relatively little effort.

It's a popular recreational activity, particularly at tropical resort destinations and at accessible scuba diving locations. Snorkeling is also employed by scuba divers when near the surface, and search and rescue teams may snorkel as part of a water-based search.

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 of rays and various flatfish. Other organisms that can be seen while snorkeling include various forms of seaweed, jellyfish, shrimp, sea turtles, various types of sea cactus and occasionally anything else which may be found in the ocean.