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.
The International Association of Nitrox and Technical Divers (IANTD) is a scuba diving organization concerned with certification and training in recreational diving, technical diving, cave diving, wreck diving, rebreather diving and diver leadership. Originally formed as the International Association of Nitrox Divers in 1985 by Dick Rutkowski it pioneered the introduction of Enriched Air Nitrox diving to the recreational diving community, before its name change in 1992 to reflect the more "technical" diving courses it had begun to teach. The European Association of Technical Divers (EATD) became part of IANTD in 1993.
Recreational diver training is the process of developing knowledge and understanding of the basic principles, and the skills and procedures for the use of scuba equipment so that the diver is able to dive for recreational purposes with acceptable risk using the type of equipment and in similar conditions to those experienced during training.
The British Sub-Aqua Club or BSAC has been recognised since 1954 by UK Sport as the national governing body of recreational diving in the United Kingdom.
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 3,500 authorized dealers, 35 regional centers, and offices all over the world.
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.
The World Recreational Scuba Training Council (WRSTC) was founded in 1999 and is dedicated to creating minimum recreational diving training standards for the various recreational scuba diving certification agencies across the world. The WRSTC restricts its membership to national or regional councils. These councils consist of individual training organizations who collectively represent at least 50% of the annual diver certifications in the member council's country or region. A national council is referred to as a RSTC.
The Federazione Italiana Attività Subacquee (FIAS) is an Italian non-profit diver training organization. It is a member of:
Global Underwater Explorers (GUE) is a scuba diving organization that provides education within recreational, technical, and cave diving. It is a nonprofit membership organization based in High Springs, Florida, United States.
Tom Mount was an American pioneering cave diver and technical diver.
Richard Rutkowski is a pioneer in the fields of hyperbaric medicine, diving medicine and diver training, especially in relation to the use of breathing gases.
A Diving certification or C-card is a document recognizing that an individual or organization authorized to do so, "certifies" that the bearer has completed a course of training as required by the agency issuing the card. This is assumed to represent a defined level of skill and knowledge in underwater diving. Divers carry a qualification record or certification card which may be required to prove their qualifications when booking a dive trip, hiring scuba equipment, having diving cylinders filled, or in the case of professional divers, seeking employment.
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.
Autonomous diver is an international minimum standard for entry-level recreational scuba diver certification. It describes the minimum requirements for basic training and certification for recreational scuba divers in international standard ISO 24801-2 and the equivalent European Standard EN 14153-2. Various organizations offer training that meets the requirements of the Autonomous Diver standard. A certification which corresponds to Autonomous Diver allows for independent diving with a dive buddy in open water. Most training organizations do not recommend exceeding a depth of 18 or 20 meters at this level of certification. After completion of this certification the training can be extended to a dive leader to ISO 24801-3 or an intermediate not defined by international standards.
Supervised diver specifies the training and certification for recreational scuba divers in international standard ISO 24801-1 and the equivalent European Standard EN 14153-1. Various diving organizations offer diving training that meets the requirements of the Supervised Diver. A diving certification which corresponds to the Supervised Diver allows for recreational diving under the direct supervision of a divemaster or recreational diving instructor in open water. Most diving organizations recommend not to exceed a diving depth of 10 to 12 metres. After the successful completion of a training equivalent to the Supervised diver, training can be extended to the Autonomous diver certification level.
Dive leader is the title of an internationally recognised recreational diving certification. The training standard describes the minimum requirements for dive leader training and certification for recreational scuba divers in international standard ISO 24801-3 and the equivalent European Standard EN 14153-3. Various organizations offer training that meets the requirements of the dive leader standard. Some agencies use the title "Dive Leader" for their equivalent certification, but several other titles are also used, "Divemaster" may be the most widespread, but "Dive Supervisor" is also used, and should not be confused with the very different status and responsibilities of a professional diving supervisor. CMAS affiliates certifications which meet the requirements of CMAS 3-star diver should meet the standard by default. The occupation of a dive leader is also known as "dive guide", and is a specialist application of a "tour guide".
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.
The following outline is provided as an overview of and topical guide to underwater diving:
Recreational scuba certification levels are the levels of skill represented by recreational scuba certification. Each certification level is associated with a specific training standard published by the certification agency, and a training programme associated with the standard., though in some cases recognition of prior learning can apply. These levels of skill can be categorised in several ways:
