Recreational diving

"Sport diving" redirects here. For the competitive underwater sport, see Sport diving (sport).

Divers off Key West, Florida

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 greater levels of training, experience and equipment to compensate for 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.

The equipment used for recreational diving is mostly open circuit scuba, though semi closed and fully automated electronic closed circuit rebreathers may be included in the scope of recreational diving. Risk is managed by training the diver in a range of standardised procedures and skills appropriate to the equipment the diver chooses to use and the environment in which the diver plans to dive. Further experience and development of skills by practice will increase the diver's ability to dive safely. Specialty training is made available by the recreational diver training industry and diving clubs to increase the range of environments and venues the diver can enjoy at an acceptable level of risk.

History

Recreational scuba diving grew out of related activities such as Snorkeling and underwater hunting. For a long time, recreational underwater excursions were limited by breath-hold time. The invention of the aqualung in 1943 by Jacques-Yves Cousteau and the wetsuit in 1952 by University of California, Berkeley physicist, Hugh Bradner and its development over subsequent years led to a revolution in recreational diving. However, for much of the 1950s and early 1960s, recreational scuba diving was a sport limited to those who were able to afford or make their own kit, and prepared to undergo intensive training to use it.

As the sport became more popular, manufacturers became aware of the potential market, and equipment began to appear that was easy to use, affordable and reliable. Continued advances in SCUBA technology, such as buoyancy compensators, improved diving regulators, wet or dry suits, and dive computers, increased the safety, comfort and convenience of the gear encouraging more people to train and use it.

Until the early 1950s, navies and other organizations performing professional diving were the only providers of diver training, but only for their own personnel and only using their own types of equipment. The first scuba diving school was opened in France to train the owners of the Cousteau and Gagnan designed twin-hose scuba. The first school to teach single hose scuba was started in 1953, in Melbourne, Australia, at the Melbourne City Baths. RAN Commander Batterham organized the school to assist the inventor of the single hose regulator, Ted Eldred. However, neither of these schools was international in nature.

There were no formal training courses available to civilians who bought the early scuba equipment. Some of the first training started in 1952 at the Scripps Institution of Oceanography where Andy Rechnitzer, Bob Dill and Connie Limbaugh taught the first scuba courses in the United States, then in 1953 Trevor Hampton created the first British diving school, the British Underwater Centre and in 1954 when Los Angeles County created an Underwater Instructor Certification Course based on the training that they received from the scientific divers of the Scripps Institution of Oceanography. Early instruction developed in the format of amateur teaching within a club environment, as exemplified by organizations such as the Scottish Sub Aqua Club and the British Sub Aqua Club from 1953, Los Angeles County from 1954 and the YMCA from 1959.

Professional instruction started in 1959 when the non-profit NAUI was formed, which later effectively was split, to form the for-profit PADI in 1966. The National Association of Scuba Diving Schools (NASDS) started with their dive center based training programs in 1962 followed by SSI in 1970. Professional Diving Instructors College was formed in 1965, changing its name in 1984 to Professional Diving Instructors Corporation (PDIC).

In 2009 PADI alone issued approximately 950,000 diving certifications. Approximately 550,000 of these PADI certifications were "entry level" certifications and the remainder were more advanced certifications.

Diving today

Scuba-diving has become a popular leisure activity, and many diving destinations have some form of dive shop presence that can offer air fills, equipment, and training. In tropical and sub-tropical parts of the world, there is a large market for 'holiday divers'; people who train and dive while on holiday, but rarely dive close to home.

Technical diving and the use of rebreathers are increasing, particularly in areas of the world where deeper wreck diving is the main underwater attraction. Generally, recreational diving depths are limited by the training agencies to a maximum of between 30 and 40 meters (100 and 130 feet), beyond which a variety of safety issues such as oxygen toxicity and nitrogen narcosis significantly increase the risk of diving using recreational diving equipment and practices, and specialized skills and equipment for technical diving are needed.

Standard equipment

Main article: Diving equipment

The standard recreational open circuit scuba equipment includes the following items:

• a Diving mask for underwater vision;
• a snorkel to aid surface swimming;
• a pair of swimfins, for mobility;
• a diving suit, which may be a dry suit, wetsuit or dive skins, or a regular swimsuit, depending on the water temperature, for thermal and environmental protection;
• a diving weighting system such as a weight belt or BCD integrated weight system, to counteract the buoyancy of the diving suit;
• a single diving cylinder (also known as scuba tank), with cylinder valve, to supply breathing air, and a harness to support it
• a buoyancy compensator, (also known as buoyancy control device or (BCD)), which is usually part of the harness used to carry the cylinder, to adjust buoyancy.
• a diving regulator to reduce the pressure of the air from the cylinder, with:
  • a primary second stage, to supply the diver with air on demand;
  • a secondary second stage (octopus) to supply emergency air to a buddy diver who needs assistance;
  • a submersible pressure gauge (SPG) (also known as contents gauge), to monitor the remaining air supply;
  • a low pressure inflation hose for the buoyancy compensator, and if applicable, for the dry suit, to inflate the BCD and suit for buoyancy control and to avoid suit squeeze.
• a dive computer (also known as personal decompression computer) or a depth gauge and timer, to monitor the dive profile, avoid decompression obligation and facilitate a controlled ascent;
• a surface marker buoy or other surface detection aid may be standard equipment in some regions to allow the surface crew and boats to monitor the diver's position.

For solo diving a bailout cylinder is considered standard for dives where there is an appreciable risk of entrapment, or where a direct controlled emergency swimming ascent is not an acceptable option to manage an out-of-air incident at any point in the planned dive profile.

Standard procedures

Main article: Scuba skills

Some skills are generally accepted by recreational diver certification agencies as necessary for any scuba diver to be considered competent to dive without direct supervision, and others are more advanced, though some diver certification and accreditation organizations may consider some of these to also be essential for minimum acceptable entry level competence. Divers are instructed and assessed on these skills during basic and advanced training, and are expected to remain competent at their level of certification, either by practice or refresher courses.

The skills include selection, functional testing, preparation and transport of scuba equipment, dive planning, preparation for a dive, kitting up for the dive, water entry, descent, breathing underwater, monitoring the dive profile (depth, time and decompression status), personal breathing gas management, situational awareness, communicating with the dive team, buoyancy and trim control, mobility in the water, ascent, emergency and rescue procedures, exit from the water, un-kitting after the dive, cleaning and preparation of equipment for storage and recording the dive, within the scope of the diver's certification. A significant amount of harmonization of training standards and standard and emergency procedures has developed over the years, largely due to organisations like World Recreational Scuba Training Council. This allows divers trained by the various certifying organisations to dive together with a minimum of confusion, which enhances safety. Diver communications is a particular aspect where most of the basic hand signals are common to most recreational diver training agencies.

This does not mean that there is no variation. There are some procedures such as emergency donation of air which are quite strongly polarized between those who advocate donation of the secondary (octopus) regulator and those who advocate donating the primary regulator. Length of regulator hose and position of the secondary second stage depend on the donation technique.

There are also variations in procedures for self rescue in an out of air situation, and in procedures for bringing an unresponsive casualty to the surface.

Solo diving, once considered technical diving and discouraged by most certification agencies, is now seen by many experienced divers and some certification agencies as an acceptable practice for those divers suitably trained and experienced. Rather than relying on the traditional buddy diving safety system, solo divers rely on self-sufficiency and are willing to take responsibility for their own safety while diving.

Buddy diving is the more generally advocated procedural alternative, on the principle that in case of an emergency, a dive buddy can assist the diver in difficulty, but this is only valid if the buddy is close enough to help, notices the problem, and is competent and willing to assist.

Training

Further information: Recreational diver training and List of diver certification organisations

Many recreational diver training organizations exist, throughout the world, offering diver training leading to certification: the issuing of a "Diving Certification Card," also known as a "C-card," or qualification card.

Recreational diver training courses range from minor specialties which require one classroom session and an open water dive, and which may be completed in a day, to complex specialties which may take several days to weeks, and require several classroom sessions, confined water skills training and practice, and a substantial number of open-water dives, followed by rigorous assessment of knowledge and skills. Details on the approximate duration of training can be found on the websites of most certification agencies, but accurate schedules are generally only available from the specific school or instructor who will present that course, as this will depend on the local conditions and other constraints.

Diving instructors affiliated to a diving certification agency may work independently or through a university, a dive club, a dive school or a dive shop. They will offer courses that should meet, or exceed, the standards of the certification organization that will certify the divers attending the course.

Diving skills

Diver training can be divided into entry level training, which are those skills and knowledge considered essential for the diver to dive unsupervised at an acceptably low level of risk by the certifying agency, and further skills and knowledge which allow better performance and extend the environmental capacity of the diver. There is a significant variation in entry level training, with some training agencies requiring the bare minimum as specified by RSTC and ISO, and others requiring a greater level of competence with associated assumption of lower risk to the diver and dive buddy. Entry level training may include skills for assisting or rescue of another diver, but this is not always the case. Divers without rescue training are routinely assigned to dive as buddy pairs to follow organizational protocols. This is not generally a contravention of the training agencies' recommendations.

Entry level

The initial training for open water certification for a person who is medically fit to dive and a reasonably competent swimmer is relatively short. The minimum number of open-water dives required for certification is usually four, but instructors are generally required by training standards to ensure that the diver is sufficiently skilled before certification is issued, and this may require further training and experience beyond the required minimum. Many dive shops in popular holiday locations offer courses intended to teach a novice to dive in a few days, which can be combined with diving on the vacation. Other instructors and dive schools will provide more thorough training, which generally takes longer.

Beyond entry level

Skills and knowledge beyond the minimum requirement are generally labelled Advanced skills, and these may include skills such as competent buoyancy control, which are included in the entry level skills by other agencies. Many skills which are considered advanced by recreational training agencies are considered basic entry-level skills for professional divers.

Training standards

Scuba diving education levels as used by ISO: PADI, CMAS, SSI and NAUI

Each diver certification agency has its own set of diver training standards for each level of certification that they issue. Although these standards are usually available on request or on the organisation's website, the assessment criteria are often not available to the public, making a direct comparison of standards difficult. Most agencies comply with the minimum requirements of the World Recreational Scuba Training Council (WRSTC) or ISO for the relevant certification (ISO 24801-2 Autonomous diver, and ISO 24801-3 Dive leader), but most certification levels are not defined by the international standards.

Under most entry-level programs (SEI, SDI, PADI, BSAC, SSAC, NAUI, SSI, and PDIC), divers can complete a certification with as few as four open water dives. This complies with the minimum requirements of ISO 24801-2 Autonomous diver. Such a qualification allows divers to rent equipment, receive air fills, and dive without supervision to depths typically restricted to 18 meters (60 feet) with an equally qualified buddy in conditions similar to, or easier than those in which they were trained. Certification agencies advise their students to dive within the scope of their experience and training, and to extend their training to suit the conditions in which they plan to dive.

In the 1980s, several agencies with DEMA collaborated to author ANSI Standard Z86.3 (1989), Minimum Course Content For Safe Scuba Diving which defines their training as the Accepted Industry Practices. The International Standards Organisation has since published ISO 24801 and ISO 24802 which define minimum training standards for two levels of recreational diver and for recreational diving instructors.

Agencies such as GUI and the commercial diver training standards of several countries, including the United Kingdom, Australia, South Africa, and Canada, consider the competence provided by the recreational diver training industry minimum standard to be inadequate for safe occupational diving, where the diver has a legal duty of care towards other members of the dive team, even though the responsibility for occupational dive planning and safety is held by a professional supervisor.

Risk

Fatality rates of 16.4 deaths per 100,000 persons per year among DAN America members and 14.4 deaths per 100,000 persons per year the British Sub-Aqua Club (BSAC) members were similar and did not change during 2000-2006. This is comparable with jogging (13 deaths per 100,000 persons per year) and motor vehicle accidents (16 deaths per 100,000 persons per year), and within the range where reduction is desirable by Health and Safety Executive (HSE) criteria,

Data for 17 million student-diver certifications during 63 million student dives over a 20-year period from 1989-2008 show a mean per capita death rateof 1.7 deaths per 100,000 student divers per year. This was lower than for insured DAN members during 2000-2006 at 16.4 deaths per 100,000 DAN members per year, but fatality rate per dive is a better measure of exposure risk, A mean annual fatality rate of 0.48 deaths per 100,000 student dives per year and 0.54 deaths per 100,000 BSAC dives per year and 1.03 deaths per 100,000 non-BSAC dives per year during 2007. The total size of the diving population is important for determining overall fatality rates, and the population estimates from the 1990s of several million U.S. divers need to be updated.

The most frequent root cause for diving fatalities is running out of or low on gas. Other factors cited include buoyancy control, entanglement or entrapment, rough water, equipment misuse or problems and emergency ascent. The most common injuries and causes of death were drowning or asphyxia due to inhalation of water, air embolism and cardiac events. Risk of cardiac arrest is greater for older divers, and greater for men than women, although the risks are equal by age 65.

Several plausible opinions have been put forward but have not yet been empirically validated. Suggested contributing factors included inexperience, infrequent diving, inadequate supervision, insufficient predive briefings, buddy separation and dive conditions beyond the diver's training, experience or physical capacity.

Specialties

There are many diving activities, and equipment and environmental specialties which require training additional to that provided by the entry level courses:

Activities:

• Snorkeling – Swimming at the surface with a diving mask and snorkel to view the shallow underwater environment.
• Free-diving also called skin diving – Swimming below the surface on breath-hold.
• Identifying surveying and monitoring sea life and freshwater life: see marine biology. This may be associated with citizen science projects and underwater photography.
• Maritime archeology or Underwater archeology – Also may be associated with citizen science and underwater photography
• Rescue Diver – Usually considered a desirable diving skill, but may be part of the requirements and function of volunteer safety divers.
• Underwater navigation – Enhanced competence at following and recording underwater routes, generally excluding the use of a guide-line, and using a compass and landmarks.
• Underwater photography - Use of photographic equipment designed or modified for underwater use for recording the environment or artistic purposes.
• Underwater search and recovery Knowledge and procedural skills for conducting underwater searches and recovering relatively small objects from underwater.
• Underwater videography – Use of video recording equipment designed or modified for underwater use for recording the environment or artistic purposes.

Environmental specialties:

• Altitude diving – knowledge and skills associated with diving in waters where the surface pressure is significantly below average sea level pressure.
• Cave diving – Knowledge and procedural skills related to managing risk in underwater cave environments.
• Deep diving – Knowledge and procedural skills related to managing risk at greater depths.
• Drift diving Procedures used to dive in currents.
• Ice diving – Knowledge and procedural skills related to managing risk in very cold water and under an ice surface layer.
• Night diving – Knowledge and procedural skills related to managing risk while diving in very low levels of natural illumination.
• Wreck diving – Knowledge and procedural skills related to managing risk while diving inside wrecks.

Equipment specialties:

• Dry suit – Knowledge and procedural skills related to managing risk associated with the use of dry suits, and optimising their usage.
• Rebreather – Knowledge and procedural skills related to managing risk related to diving with rebreathers.
• Side mount diving – Knowledge and procedural skills related to use of side-mounted scuba equipment.
• Nitrox diving – Knowledge related to managing risk when using nitrox as a breathing gas.
• Recreational trimix diving – Knowledge related to managing risk when using trimix as a breathing gas.

Many diver training agencies such as ACUC, BSAC, CMAS, IANTD, NAUI, PADI, PDIC, SDI, and SSI offer training in these areas, as well as opportunities to move into professional instruction, technical diving, commercial diving and others.

Venues for diving

Most bodies of water can be used as dive sites:

• Seas and Oceans - these consist of salt water and a huge variety of flora and fauna.
• Lakes - small lakes are often used for diver training. Large lakes have many features of seas including wrecks and a variety of aquatic life. Some lakes are high in altitude, and they require special considerations for diving. See Altitude diving
• Caves - these are more adventurous and dangerous than normal diving. See cave diving.
• Rivers - are often shallow, murky and may have strong currents.
• Man-made lakes, such as dams and flooded clay pits, gravel pits and quarries, often have low visibility. Disused and flooded quarries are popular in inland areas for diver training as well as recreational diving. Rock quarries may have reasonable underwater visibility - there is often little mud or silt to create mid-water particles that cause low visibility, and the lack of flow allows silt to settle on the bottom, where it may later be kicked up by unskilled divers to temporarily reduce visibility locally. As they are not natural environments, and usually privately owned, quarries may contain objects intentionally placed for divers to explore, such as sunken boats, automobiles, aircraft, or structures like grain silos and gravel chutes.

Dive site features

Many types of underwater features make an interesting dive site, for example:

NASA image [1] showing locations of significant coral reefs, which are often sought out by divers for their abundant, diverse life forms.

• Wildlife at the site. Popular examples are coral, sponges, fish, sting rays, molluscs, cetaceans, seals, sharks and crustaceans.
• The Topography of the site. Coral reefs, drop offs (underwater cliffs), rock reefs, gullies and caves can be spectacular. Deep dive sites mean divers must reduce the time they spend because more gas is breathed at depth and decompression sickness risks increase. Shallow regions can be investigated by snorkeling.
• Historical or cultural items at the site. Ship wrecks and sunken aircraft, apart from their historical value, form artificial habitats for marine fauna making them attractive dive sites.
• Underwater visibility varies widely. Poor visibility is caused by particles in the water, such as mud, sand, plankton and sewage. Dive sites that are close to sources of these particles, such as human settlements and river estuaries, are more prone to poor visibility. Currents can stir up the particles. Diving close to the sediments on the bottom can result in the particles being kicked up by wash from the divers fins.
• Temperature. Warm water diving is comfortable and convenient. Although cold water is uncomfortable and can cause hypothermia it can be interesting because different species of underwater life thrive in cold conditions. For cold water divers tend to prefer dry suits with inner thermal clothing which offer greater thermal protection, although they require additional knowledge and skill to use safely.
• Currents. Currents can transport nutrients to underwater wildlife increasing the variety and density of that life at the site. Currents can also be dangerous to divers as they can result in the diver being swept away from his or her surface support. Currents that meet large underwater obstructions can cause strong up or down flow that can be dangerous because it may cause the diver to rapidly change depth, with possible loss of buoyancy control and increased risk of barotrauma and decompression sickness.

See also

• Free-diving
• List of reefs
• Scuba diving
• Snorkelling
• Snuba
• Technical diving
• Recreational dive sites
• Recreational diver training
• Diving Equipment and Marketing Association

External links

• Sport Diver Magazine - The official magazine of the PADI Diving Society
• Scuba Earth - An interactive scuba diving map of dive sites from all around the world.
• On the Red Sea, as Hotels Go Up, Divers Head Down The New York Times (April 8, 2007)
• BSAC Where to Dive - Dive site atlas from the British Sub Aqua Club
• Dive Site Directory - Global dive site location atlas created with contributions from the diving community
• ScubaZine Divers Community - Global GPS based dive site and services location that can be viewed in Google Earth
• Dive Sites - Interactive scuba diving site locator, a search engine for diving sites.