Recreational diving
Encyclopedia
Underwater diving
Underwater diving is the practice of going underwater, either with breathing apparatus or by breath-holding .Recreational diving is a popular activity...
that uses SCUBA equipment
Scuba set
A scuba set is an independent breathing set that provides a scuba diver with the breathing gas necessary to breathe underwater during scuba diving. It is much used for sport diving and some sorts of work diving....
for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving
Technical diving
Technical diving is a form of scuba diving that exceeds the scope of recreational diving...
", a more demanding aspect of the sport which requires greater levels of training, experience and equipment.The distinction (if a distinction exists) between "recreational diving" and "technical diving" is a source of some debate within the diving community, but most major diving training agencies recognise a broad distinction (see for example, PADI
Professional Association of Diving Instructors
The Professional Association of Diving Instructors is the world's largest recreational diving membership and diver training organization founded in 1966 by John Cronin and Ralph Erickson...
and DSAT
Diving Science and Technology
Diving Science and Technology is a corporate affiliate of the Professional Association of Diving Instructors and the developer of the Recreational Dive Planner. DSAT has held scientific workshops for diver safety and education....
, and SDI
SCUBA Diving International
Scuba Diving International is a SCUBA training and certification agency. It is the recreational arm of Technical Diving International, the world’s largest technical diver training organization...
and TDI
Technical Diving International
Technical Diving International is the largest technical diving certification agency in the world. As one of the first agencies to provide training in mixed gas diving and rebreathers, TDI is seen as an innovator of new diving techniques and programs which previously were not available to the...
).
History
Recreational scuba diving grew out of related activities such as SnorkelingSnorkeling
Snorkeling is the practice of swimming on or through a body of water while equipped with a diving mask, a shaped tube called a snorkel, and usually swimfins. In cooler waters, a wetsuit may also be worn...
and underwater hunting
Spearfishing
Spearfishing is an ancient method of fishing that has been used throughout the world for millennia. Early civilizations were familiar with the custom of spearing fish from rivers and streams using sharpened sticks....
. For a long time, recreational underwater
Underwater
Underwater is a term describing the realm below the surface of water where the water exists in a natural feature such as an ocean, sea, lake, pond, or river. Three quarters of the planet Earth is covered by water...
excursions were limited by the amount of breath that could be held. However, the invention of the aqualung
Aqua-lung
Aqua-Lung was the original name of the first open-circuit free-swimming underwater breathing set in reaching worldwide popularity and commercial success...
in 1943 by Jacques-Yves Cousteau
Jacques-Yves Cousteau
Jacques-Yves Cousteau was a French naval officer, explorer, ecologist, filmmaker, innovator, scientist, photographer, author and researcher who studied the sea and all forms of life in water...
and the wetsuit
Wetsuit
A wetsuit is a garment, usually made of foamed neoprene, which is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports, providing thermal insulation, abrasion resistance and buoyancy. The insulation properties depend on bubbles of gas enclosed within the material,...
in 1953 by Georges Beuchat
Georges Beuchat
Georges Beuchat was a French inventor, diver, businessman and emblematic pioneer of underwater activities and founder of Beuchat.Throughout his lifetime, Georges Beuchat never ceased developing products which have significantly enhanced underwater activity as we know it today...
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, modern diving regulator
Diving regulator
A diving regulator is a pressure regulator used in scuba or surface supplied diving equipment that reduces pressurized breathing gas to ambient pressure and delivers it to the diver. The gas may be air or one of a variety of specially blended breathing gases...
s, wet or dry suit
Dry suit
A dry suit or drysuit provides thermal insulation or passive thermal protection to the wearer while immersed in water, and is worn by divers, boaters, water sports enthusiasts, and others who work or play in or near cold water. A dry suit normally protects the whole body except the head, hands, and...
s, and dive computer
Dive computer
A dive computer or decompression meter is a device used by a scuba diver to measure the time and depth of a dive so that a safe ascent profile can be calculated and displayed so that the diver can avoid decompression sickness.- Purpose :...
s, 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 created in France to train the owners of the Jacques Yves Cousteau and Emile Gagnan designed double hose scuba. The first school to teach the modern 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 were international in nature.
There were no training courses, in the modern sense, available to civilians who bought the first scuba equipment. Some of the first training started in 1953 Trevor Hampton created the first British diving school, the British Underwater Centre and 1954 when Los Angeles County created an Underwater Instructor Certification Course. Early instruction increased in the form of amateur teaching within a club environment, as exemplified by organizations such as the Scottish Sub-Aqua Club and the British Sub Aqua Club
British Sub Aqua Club
The British Sub-Aqua Club or BSAC has been recognised since 1954 by the Sports Council as the governing body of recreational diving in the United Kingdom....
from 1953, Los Angeles County from 1954 and the YMCA from 1959.
Professional instruction started in 1959 when the non-profit NAUI
National Association of Underwater Instructors
The National Association of Underwater Instructors is a non-profit 501 association of SCUBA instructors. It was officially CE and ISO certified in May 2007 in all three diver levels and both instructor levels.-History:...
was formed, which later effectively was split, to form the for-profit PADI
Professional Association of Diving Instructors
The Professional Association of Diving Instructors is the world's largest recreational diving membership and diver training organization founded in 1966 by John Cronin and Ralph Erickson...
in 1966.
NASDS the National Association of Scuba Diving Schools started with their Dive Center based Training programs in 1962 followed by SSI
Scuba Schools International
Scuba Schools International or SSI is an organization that teaches the skills involved in scuba diving and supports Dive Businesses and Dive Resorts.SSI has well over 2,500 authorized dealers and 35 Regional Centers and Area Offices all over the World....
in 1970.
PDIC
Professional Diving Instructors Corporation
The Professional Diving Instructors Corporation is an international SCUBA training and certification agency. It has an estimated 5 million active recreational divers....
professional diving instructors college was formed in 1965, later changing its name to PDIC professional diving instructors Corporation in 1984, providing training in a retail environment.
Today, PADI alone issues approximately 950,000 diving certifications a year.
Diving today
Further developments in technology have reduced the cost of training and diving. Scuba-diving has become a popular leisure activity, and many diving locations 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 in 'holiday divers'; people who train and dive while on holiday, but rarely dive close to home.
Technical diving
Technical diving
Technical diving is a form of scuba diving that exceeds the scope of recreational diving...
and use of rebreather
Rebreather
A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycled exhaled gas. This recycling reduces the volume of breathing gas used, making a rebreather lighter and more compact than an open-circuit breathing set for the same duration in environments where...
s are increasing, particularly in areas of the world where deeper wreck diving
Wreck diving
Wreck diving is a type of recreational diving where shipwrecks are explored. Although most wreck dive sites are at shipwrecks, there is an increasing trend to scuttle retired ships to create artificial reef sites...
is the main underwater attraction. Generally, recreational diving depths are limited to a maximum of between 30 and 40 meters (100 and 130 feet), beyond which a variety of safety issues make it unsafe to dive using recreation diving equipment and practices, and specialized training and equipment for technical diving
Technical diving
Technical diving is a form of scuba diving that exceeds the scope of recreational diving...
are needed.
Standard equipment
- Diving maskDiving maskA diving mask is an item of diving equipment that allows scuba divers, free-divers, and snorkelers to see clearly underwater. When the human eye is in direct contact with water as opposed to air, its normal environment, light entering the eye is refracted by a different angle and the eye is unable...
or full face diving maskFull face diving maskA full-face diving mask is a type of diving mask that seals the whole of the diver's face from the water and contains a mouthpiece or demand valve that provides the diver with breathing gas...
and snorkel - SwimfinSwimfinSwimfins, swim fins, fins or flippers are worn on the foot or leg and made from finlike rubber or plastic, to aid movement through the water in water sports activities such as swimming, bodyboarding, bodysurfing, kneeboarding, riverboarding, and various types of underwater diving.Scuba divers use...
s or scuba fins - Dry suitDry suitA dry suit or drysuit provides thermal insulation or passive thermal protection to the wearer while immersed in water, and is worn by divers, boaters, water sports enthusiasts, and others who work or play in or near cold water. A dry suit normally protects the whole body except the head, hands, and...
, wetsuitWetsuitA wetsuit is a garment, usually made of foamed neoprene, which is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports, providing thermal insulation, abrasion resistance and buoyancy. The insulation properties depend on bubbles of gas enclosed within the material,...
or regular swimsuit, depending on the water temperature - Buoyancy compensator or buoyancy control device (BCD)
- Diving weighting systemDiving weighting systemDivers wear weighting systems, weight belts or weights, generally made of lead, to counteract the buoyancy of other diving equipment, such as diving suits and aluminium diving cylinders...
or weight belt - Diving cylinderDiving cylinderA diving cylinder, scuba tank or diving tank is a gas cylinder used to store and transport high pressure breathing gas as a component of a scuba set. It provides gas to the scuba diver through the demand valve of a diving regulator....
or scuba tank - Diving regulatorDiving regulatorA diving regulator is a pressure regulator used in scuba or surface supplied diving equipment that reduces pressurized breathing gas to ambient pressure and delivers it to the diver. The gas may be air or one of a variety of specially blended breathing gases...
- Contents gauge or submersible pressure gauge (SPG)
- Dive computerDive computerA dive computer or decompression meter is a device used by a scuba diver to measure the time and depth of a dive so that a safe ascent profile can be calculated and displayed so that the diver can avoid decompression sickness.- Purpose :...
or depth gaugeDepth gaugeA depth gauge is a pressure gauge that displays the equivalent depth in water. It is a piece of diving equipment often used by SCUBA divers.Most modern diving depth gauges have an electronic mechanism and digital display. Older types used a mechanical mechanism and analogue display.A diver uses a...
and timerDiving watchA diving watch is a watch designed for underwater diving that features, as a minimum, a water resistance greater than , the equivalent of . The typical diver's watch will have a water resistance of around , though modern technology allows the creation of diving watches that can go much deeper... - Surface marker buoySurface Marker BuoyA surface marker buoy, SMB or simply a blob is an inflatable buoy used by scuba divers, with a line, to indicate the diver's position to their surface safety boat while the diver is underwater.- Standard buoy :...
or other surface detection aid
Issues
There are several recreational diving issues that are currently topics of discussion within the diving community. They include:Training levels
There is a certain amount of disquiet over the level of training and experience necessary to qualify as a diver. Under most entry-level programs (SEI, SDISCUBA Diving International
Scuba Diving International is a SCUBA training and certification agency. It is the recreational arm of Technical Diving International, the world’s largest technical diver training organization...
, PADI
Professional Association of Diving Instructors
The Professional Association of Diving Instructors is the world's largest recreational diving membership and diver training organization founded in 1966 by John Cronin and Ralph Erickson...
, BSAC, SSAC, NAUI
National Association of Underwater Instructors
The National Association of Underwater Instructors is a non-profit 501 association of SCUBA instructors. It was officially CE and ISO certified in May 2007 in all three diver levels and both instructor levels.-History:...
, SSI
Scuba Schools International
Scuba Schools International or SSI is an organization that teaches the skills involved in scuba diving and supports Dive Businesses and Dive Resorts.SSI has well over 2,500 authorized dealers and 35 Regional Centers and Area Offices all over the World....
, and PDIC
Professional Diving Instructors Corporation
The Professional Diving Instructors Corporation is an international SCUBA training and certification agency. It has an estimated 5 million active recreational divers....
, divers can complete a certification with as few as four 'open water' dives. Such a qualification allows divers to rent equipment, receive air fills, and dive without any higher supervision to depth restrictions of typically 60 feet with a buddy. Critics claim that four dives is too few to prepare new divers for such a level of responsibility, and that either the total should be raised or the certification qualified. Certification agencies normally answer that they advise their students to dive within the envelope of their experience and training, and to seek to extend their training to Advanced Open Water, Enriched Air Nitrox, and beyond. In the 1980s, several agencies with DEMA collaborated to author ANSI Standard Z86.3 (1989), Minimum Course Content For Safe Scuba Diving which now serves to limit their potential liability from lawsuits on training adequacy issues by defining their training as the definition of Accepted Industry Practices.
Regular vs. leisure
Some divers see a split beginning to emerge in recreational diving between regular recreational divers, who often dive in their home communities, and leisure divers, characterized as those who dive occasionally, normally when abroad on holiday and in more benign conditions. It is sometimes observed that there is a tension between the two, and that leisure divers are often inexperienced, either under-trained or over-qualified, and sustain only a minimal empathy with the underwater world. The call is usually not that these divers be restrained from diving, but that they be encouraged to dive more regularly in their home communities so as to gain experience and support their local diving scene. However, as recreational diving has a very low accident and death rate, it is a commonly claimed view that current training requirements are adequate.Specialties
There are many diving activities which need further training than that provided by the initial courses:- Altitude divingAltitude divingAltitude diving is scuba diving where the surface is 300 meters or more above sea level . The U.S. Navy tables recommend that no alteration be made for dives at altitudes lower than 91 meters and dives between 91 meters and 300 meters correction is required for dives over 44 meters sea water...
- Cave divingCave divingCave diving is a type of technical diving in which specialized equipment is used to enable the exploration of caves which are at least partially filled with water. In the United Kingdom it is an extension of the more common sport of caving, and in the United States an extension of the more common...
- Deep divingDeep divingThe meaning of the term deep diving is a form of technical diving. It is defined by the level of the diver's diver training, diving equipment, breathing gas, and surface support:...
- Drift divingDrift divingDrift diving is a type of recreational diving where the diver is transported by the currents caused by the tide or in a river.The current gives the diver the impression of flying and allows the diver to cover long distances underwater, possibly seeing more habitats and formations than usual...
- Free-divingFree-divingFreediving is any of various aquatic activities that share the practice of breath-hold underwater diving. Examples include breathhold spear fishing, freedive photography, apnea competitions and, to a degree, snorkeling...
also called skin diving - Ice divingIce divingIce diving is a type of penetration diving where the dive takes place under ice. Because diving under ice places the diver in an overhead environment typically with only a single entry/exit point, it is considered an advanced type of diving requiring special training...
- Identifying and surveying sea life and freshwater life: see marine biologyMarine biologyMarine biology is the scientific study of organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather...
- Maritime archeology or Underwater archeology
- Night divingNight divingNight diving is a type of recreational diving which takes place in darkness. The diver can experience a different underwater environment at night, because many marine animals are nocturnal....
- SnorkelingSnorkelingSnorkeling is the practice of swimming on or through a body of water while equipped with a diving mask, a shaped tube called a snorkel, and usually swimfins. In cooler waters, a wetsuit may also be worn...
- Underwater navigationUnderwater navigationUnderwater navigation is the common reference term for navigation techniques learned by Scuba divers in order to accurately navigate in an underwater environment....
- Underwater photographyUnderwater photographyUnderwater photography is the process of taking photographs while under water. It is usually done while scuba diving, but can be done while snorkeling or swimming.-Overview:...
- Underwater search and recoveryUnderwater search and recoveryUnderwater search and recovery is the process of locating and recovering underwater objects by divers. Although most underwater search and recovery is done by commercial divers as part of professional marine salvage operations, search and recovery diving is also frequently undertaken as part of...
- Underwater videographyUnderwater videographyUnderwater videography is a video production, the branch of underwater photography concerned with capturing underwater moving images either as a recreational diving or commercial documentary, or filmmaking activity.-Limitations:...
- Wreck divingWreck divingWreck diving is a type of recreational diving where shipwrecks are explored. Although most wreck dive sites are at shipwrecks, there is an increasing trend to scuttle retired ships to create artificial reef sites...
- Nitrox diving
Many diver training
Diver training
Diver training is the process of developing skills and building experience in the use of diving equipment and techniques so that the diver is able to dive safely and have fun....
agencies such as ACUC, BSAC, CMAS, IANTD, NAUI, PADI, PDIC, SDI, SSI and YMCA offer training in these areas, as well as opportunities to move into professional instruction, technical diving
Technical diving
Technical diving is a form of scuba diving that exceeds the scope of recreational diving...
, commercial diving
Commercial Diving
Professional diving is a type of diving where the divers are paid for their work. There are several branches of professional diving, the most well known of which is probably commercial diving...
and others.
Bodies of water for diving
Most bodies of water can be used as dive sites:- SeaSeaA sea generally refers to a large body of salt water, but the term is used in other contexts as well. Most commonly, it means a large expanse of saline water connected with an ocean, and is commonly used as a synonym for ocean...
s and Oceans - these consist of salt water and a huge variety of flora and fauna. - Lakes - small lakes are often used for diver trainingDiver trainingDiver training is the process of developing skills and building experience in the use of diving equipment and techniques so that the diver is able to dive safely and have fun....
. Large lakes have many features of seas including wrecks and a variety of marine lifeMarine biologyMarine biology is the scientific study of organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather...
. Man-made lakes, such as clay pitClay pitA clay pit is a quarry or mine for the extraction of clay, which is generally used for manufacturing pottery, bricks or Portland cement.The brickyard or brickworks is often located alongside the clay pit to reduce the transport costs of the raw material. These days pottery producers are often not...
s and gravel pitGravel pitGravel pit is the term for an open cast working for extraction of gravel. Gravel pits often lie in river valleys where the water table is high, so they may fill naturally with water to form ponds or lakes. Old, abandoned gravel pits are normally used either as nature reserves, or as amenity areas...
s, often have lower visibility. Some lakes are high in altitude, and they require special considerations for diving. See Altitude divingAltitude divingAltitude diving is scuba diving where the surface is 300 meters or more above sea level . The U.S. Navy tables recommend that no alteration be made for dives at altitudes lower than 91 meters and dives between 91 meters and 300 meters correction is required for dives over 44 meters sea water... - Caves - these are more adventurous and dangerous than normal diving. See cave divingCave divingCave diving is a type of technical diving in which specialized equipment is used to enable the exploration of caves which are at least partially filled with water. In the United Kingdom it is an extension of the more common sport of caving, and in the United States an extension of the more common...
. - Rivers - are often shallow, murky and have strong currents.
- QuarriesScuba diving quarryScuba diving quarries are depleted or abandoned rock quarries that have been allowed to fill with ground water, and rededicated to the purpose of scuba diving....
- abandoned rock quarries are popular in inland areas for diver training as well as recreational diving. Rock quarries also have reasonable underwater visibility - there is often little mud or sand to create mid-water particles that cause low visibility. As they are not "wild" and usually privately owned, quarries often contain objects intentionally placed for divers to explore, such as sunken boats, automobiles, aircraft, and even structures like grain silos and gravel chutes.
Dive site features
Many types of underwaterUnderwater
Underwater is a term describing the realm below the surface of water where the water exists in a natural feature such as an ocean, sea, lake, pond, or river. Three quarters of the planet Earth is covered by water...
feature make an interesting dive site, for example:
- Wildlife at the site. Popular examples are coralCoralCorals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
, spongeSea spongeSponges are animals of the phylum Porifera . Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells, but can also have...
s, fishFishFish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, sting rays, molluscs, cetaceaCetaceaThe order Cetacea includes the marine mammals commonly known as whales, dolphins, and porpoises. Cetus is Latin and is used in biological names to mean "whale"; its original meaning, "large sea animal", was more general. It comes from Ancient Greek , meaning "whale" or "any huge fish or sea...
ns, sealPinnipedPinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...
s, sharkSharkSharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
s and crustaceanCrustaceanCrustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s.
- The Topography of the site. Coral reefCoral reefCoral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s, drop offs (underwater cliffCliffIn geography and geology, a cliff is a significant vertical, or near vertical, rock exposure. Cliffs are formed as erosion landforms due to the processes of erosion and weathering that produce them. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually...
s), rock reefReefIn nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s, gullies and caveCaveA cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...
s can be spectacular. Deep dive sites mean divers must reduce the time they spend because more gas is breathed at depth and decompression sicknessDecompression sicknessDecompression sickness describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization...
risks increase. Shallow regions can be investigated by snorkelingSnorkelingSnorkeling is the practice of swimming on or through a body of water while equipped with a diving mask, a shaped tube called a snorkel, and usually swimfins. In cooler waters, a wetsuit may also be worn...
.
- Historical or cultural items at the site. Ship wrecks and sunken aircraftAircraftAn aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
, apart from their historical value, form artificial habitatsHabitat (ecology)A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
for marine fauna making them attractive dive sites.
- Underwater visibilityVisibilityIn meteorology, visibility is a measure of the distance at which an object or light can be clearly discerned. It is reported within surface weather observations and METAR code either in meters or statute miles, depending upon the country. Visibility affects all forms of traffic: roads, sailing...
varies widely. Poor visibility is caused by particles in the water, such as mudMudMud is a mixture of water and some combination of soil, silt, and clay. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone . When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds...
, sandSandSand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
and sewageSewageSewage is water-carried waste, in solution or suspension, that is intended to be removed from a community. Also known as wastewater, it is more than 99% water and is characterized by volume or rate of flow, physical condition, chemical constituents and the bacteriological organisms that it contains...
. 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 seabed can result in the particles being kicked up by the divers fins.
- Temperature. Warm water diving is comfortable and convenient. Although cold water is uncomfortable and can cause hypothermiaHypothermiaHypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...
it can be interesting because different species of underwater life thrive in cold conditions. Cold water means divers tend to prefer Dry suits with inner thermal clothing which offer greater thermal protection although require training and experience to use properly.
- Currents. Tidal currentTideTides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the moon and the sun and the rotation of the Earth....
s can transport nutrientNutrientA nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
s 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. Tidal currents that meet solid underwater vertical surfaces can cause strong up or down currents that are dangerous because they may cause the diver to lose buoyancyBuoyancyIn physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...
control risking barotraumaBarotraumaBarotrauma is physical damage to body tissues caused by a difference in pressure between an air space inside or beside the body and the surrounding fluid...
.
External links
- Sport Diver Magazine - The official magazine of the PADI Diving Society
- 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 ClubBritish Sub Aqua ClubThe British Sub-Aqua Club or BSAC has been recognised since 1954 by the Sports Council as the governing body of recreational diving in the United Kingdom....
- 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 EarthGoogle EarthGoogle Earth is a virtual globe, map and geographical information program that was originally called EarthViewer 3D, and was created by Keyhole, Inc, a Central Intelligence Agency funded company acquired by Google in 2004 . It maps the Earth by the superimposition of images obtained from satellite...