SNUBA is a cross between SCUBA and snorkeling (or SCUBA and free diving. The idea is to sustain a greater amount of time underwater and greater maneuverability. How they achive this is by running a long tube to an air station on a raft (or possibly a boat), and back to the regulator being worn by the person. It is possible to SNUBA wearing nothing but your regulator, but the most common equipment used is a weightbelt, mask, and fins. Less commonly, you will also find a SNUBA diver wearing a wetsuit or drysuit as well.
Having less equipment has the advantage of more freedom of movement when compared to SCUBA. People who SNUBA often say the effect is that they are flying. The disadvantage is that you are tethered to the point where the air station is located. This is too much of a disadvantage as you might think, as many SNUBA divers frequent coral reefs and caves.
Many people enjoy SNUBA from ages eight an up. SNUBA is practiced most places you will find SCUBA diving, and all places you find snorkeling. SNUBA diving does not require a special license, but many places that offer SNUBA require some sort of verification that you have been trained, or offer courses for it.
The word SNUBA is a registered trademark of Snuba International, Inc.