The Professional Association of Diving Instructors (PADI) is a recreational diving membership and diver training organization founded in 1966 by John Cronin and Ralph Erickson. PADI courses range from entry level to advanced recreational diver certification. Further, they provide several specialized diving skills courses connected with specific equipment or conditions, some diving related informational courses and a range of recreational diving instructor certifications. They also offer various technical diving courses. As of 2023, PADI is reported to have issued 29 million scuba certifications.
Freediving, free-diving, free diving, breath-hold diving, or skin diving, is a mode of underwater diving that relies on breath-holding until resurfacing rather than the use of breathing apparatus such as scuba gear.
A divemaster (DM) is a role that includes organising and leading recreational dives, particularly in a professional capacity, and is a qualification used in many parts of the world in recreational scuba diving for a diver who has supervisory responsibility for a group of divers and as a dive guide. As well as being a generic term, 'Divemaster' is the title of the first professional rating of many training agencies, such as PADI, SSI, SDI, NASE, except NAUI, which rates a NAUI Divemaster under a NAUI Instructor but above a NAUI Assistant Instructor. The divemaster certification is generally equivalent to the requirements of ISO 24801-3 Dive Leader.
A dive computer, personal decompression computer or decompression meter is a device used by an underwater diver to measure the elapsed time and depth during a dive and use this data to calculate and display an ascent profile which, according to the programmed decompression algorithm, will give a low risk of decompression sickness. A secondary function is to record the dive profile, warn the diver when certain events occur, and provide useful information about the environment.
Recreational diving or sport diving is diving for the purpose of leisure and enjoyment, usually when using scuba equipment. The term "recreational diving" may also be used in contradistinction to "technical diving", a more demanding aspect of recreational diving which requires more training and experience to develop the competence to reliably manage more complex equipment in the more hazardous conditions associated with the disciplines. Breath-hold diving for recreation also fits into the broader scope of the term, but this article covers the commonly used meaning of scuba diving for recreational purposes, where the diver is not constrained from making a direct near-vertical ascent to the surface at any point during the dive, and risk is considered low.
Scuba Schools International (SSI) is a for-profit organization that teaches the skills involved in scuba diving and freediving, and supports dive businesses and resorts. SSI has over 2,500 authorized dealers, 35 regional centers, and offices all over the world.
PADI AWARE Foundation is an environmental nonprofit organization with three registered charities in the United Kingdom, United States, and Australia. Their mission is to drive local initiatives contributing to global ocean conservation efforts, through engagement with the international community of professional and recreational scuba divers via the Professional Association of Diving Instructors (PADI).
Advanced Open Water Diver (AOWD) is a recreational scuba diving certification level provided by several diver training agencies. Agencies offering this level of training under this title include Professional Association of Diving Instructors (PADI), and Scuba Schools International (SSI). Other agencies offer similar training under different titles. Advanced Open Water Diver is one step up from entry level certification as a beginner autonomous scuba diver. A major difference between Autonomous diver equivalent Open Water Diver (OWD) certification and AOWD is that the depth limit is increased from 18 to 30 metres.
Johnson Outdoors Inc. produces outdoor recreational products such as watercraft, diving equipment, camping gear, and outdoor clothing. It has operations in 24 locations worldwide, employs 1,400 people and reports sales of more than $315 million. Helen Johnson-Leipold, one of Samuel Curtis Johnson, Jr.'s four children, has run the company since 1999.
Scuba Diving International (SDI) is a Scuba training and certification agency. It is the recreational arm of Technical Diving International, a technical diver training organization.
Karoline Mariechen "Karol" Meyer is a Brazilian free-diver. She is a Guinness Book of World Records record holder for apnea free diving, with a dive of 121 m (328 ft) and another static record with O2 for 18 minutes and 32 seconds.
Confédération Mondiale des Activités Subaquatiques (CMAS) is an international federation that represents underwater activities in underwater sport and underwater sciences, and oversees an international system of recreational snorkel and scuba diver training and recognition. It is also known by its English name, the World Underwater Federation, and its Spanish name, Confederación Mundial De Actividades Subacuáticas. Its foundation in Monaco during January 1959 makes it one of the world's oldest underwater diving organisations.
TangaReef is a company providing online booking for scuba diving, snorkeling and freediving around the world. The service allows tourists to find dive centers based on location, activities and instruction language. Divers can conveniently make bookings online as well as review and rate dive centers. TangaReef has been compared to Hotels.com, with a focus on dive centers. The website is currently in English. It provides online bookings for more than 60 dive centers in popular tourist destinations such as Thailand, the Philippines, Egypt, and the Caribbean with Mexico, Curaçao, Colombia, the Virgin Islands and Jamaica.
Julie Andersen is an activist and a founder of Shark Angels, a nonprofit organization focused on shark conservation.
Dive RAID International is a dive training organization which was founded in 2007 to support diver training for the Poseidon Mk VI Discovery Rebreather. It has since extended its scope to include open circuit scuba training and training for both recreational and technical diving sectors as well as snorkeling and freediving.
The history of scuba diving is closely linked with the history of the equipment. By the turn of the twentieth century, two basic architectures for underwater breathing apparatus had been pioneered; open-circuit surface supplied equipment where the diver's exhaled gas is vented directly into the water, and closed-circuit breathing apparatus where the diver's carbon dioxide is filtered from the exhaled breathing gas, which is then recirculated, and more gas added to replenish the oxygen content. Closed circuit equipment was more easily adapted to scuba in the absence of reliable, portable, and economical high pressure gas storage vessels. By the mid-twentieth century, high pressure cylinders were available and two systems for scuba had emerged: open-circuit scuba where the diver's exhaled breath is vented directly into the water, and closed-circuit scuba where the carbon dioxide is removed from the diver's exhaled breath which has oxygen added and is recirculated. Oxygen rebreathers are severely depth limited due to oxygen toxicity risk, which increases with depth, and the available systems for mixed gas rebreathers were fairly bulky and designed for use with diving helmets. The first commercially practical scuba rebreather was designed and built by the diving engineer Henry Fleuss in 1878, while working for Siebe Gorman in London. His self contained breathing apparatus consisted of a rubber mask connected to a breathing bag, with an estimated 50–60% oxygen supplied from a copper tank and carbon dioxide scrubbed by passing it through a bundle of rope yarn soaked in a solution of caustic potash. During the 1930s and all through World War II, the British, Italians and Germans developed and extensively used oxygen rebreathers to equip the first frogmen. In the U.S. Major Christian J. Lambertsen invented a free-swimming oxygen rebreather. In 1952 he patented a modification of his apparatus, this time named SCUBA, an acronym for "self-contained underwater breathing apparatus," which became the generic English word for autonomous breathing equipment for diving, and later for the activity using the equipment. After World War II, military frogmen continued to use rebreathers since they do not make bubbles which would give away the presence of the divers. The high percentage of oxygen used by these early rebreather systems limited the depth at which they could be used due to the risk of convulsions caused by acute oxygen toxicity.
Dottie May Frazier was an American diver, designer, and dive shop owner. Her life is chronicled in her autobiography, Trailblazer: The Extraordinary Life of Diving Pioneer, Dottie Frazier. She was the first female scuba instructor and the first female dive shop owner.
Cristina Zenato is an Italian-born shark diver and conservationist. She is known for her work with Caribbean reef sharks in The Bahamas.
