Snuba
Snuba is form of surface-supplied diving that uses an underwater breathing system developed by Snuba International. The origin of the word "Snuba" may be a portmanteau of "snorkel" and "scuba", as it bridges the gap between the two. Alternatively, some have identified the term as an acronym for "Surface Nexus Underwater Breathing Apparatus", though this may have been ascribed retroactively to fit the portmanteau. The swimmer uses swimfins, a diving mask, weights, and diving regulator as in scuba diving. Instead of coming from tanks strapped to the diver's back, air is supplied from long hoses connected to  compressed air cylinders contained in a specially designed flotation device at the surface. Snuba often serves as a form of introductory diving, in the presence of a professionally trained guide, but requires no scuba certification. Popularity. The snuba system was devised in 1989 by California diver Michael Stafford. It was then developed and patented in 1990 by Snuba International, based in Diamond Springs, California, who own the trademark and license it as a touring program. Snuba diving is a popular guided touring activity in tropical tourist locations such as Hawaii, Thailand, the Caribbean and México. Snuba is also popular because  no certification or prior dive experience is required. Participants need only to be at least eight years of age, have a basic swimming ability, and be comfortable in the water. Its popularity as a first timer's experience can be attributed to several factors. Disadvantages. In strong current, wave action, or breeze, the combination of underwater hose and surface raft can pull quite hard on a diver. Snuba is therefore best used in areas where wind, waves and current are negligible. Since all snuba use is offered by licensed snuba operators who operate the systems as a guided tour, the  possibility of being subjected to strong current, high waves or high wind is not likely. However it is beneficial if one employee of the snuba operator remains on the surface to monitor conditions. Since the depth of a snuba dive is limited to about , decompression sickness is not likely to be a problem. However, as the snuba diver is breathing compressed air, there is still a risk of injury or death due to barotrauma, which is a more severe hazard at shallow depths if divers ascend as little as a few feet without venting the expanding air in their lungs . This danger is easily avoided by breathing normally and continuously while ascending. This point is thoroughly covered in snuba pre-dive briefings, and monitored by the dive guide throughout the dive by watching for the continual release of bubbles from each diver. According to the snuba web site, since operation started in 1989, more than 5 million dives have been conducted without injury or fatality, but there appears to have been at least one fatality to a snuba diver, in April 2014. The cause of death is not reported, so it is unknown if the death was related specifically to  the use of snuba, or to other causes. It is not known if any other dives with injury or fatality have occurred. The snuba liability release form releases the operators and developers of the snuba system from any liability or responsibility for damage, injury or death due to neglect, system failure or any other reason. Yet, there are many non-official reports about inadequate training.