Great Barrier Reef, Australia
An underwater environment is an environment of, and immersed in, liquid water in a natural or artificial feature (called a body of water), such as an ocean, sea, lake, pond, reservoir, river, canal, or aquifer. Some characteristics of the underwater environment are universal, but many depend on the local situation.
Liquid water has been present on Earth for most of the history of the planet. The underwater environment is thought to be the place of the origin of life on Earth, and it remains the ecological region most critical to the support of life and the natural habitat of the majority of living organisms. Several branches of science are dedicated to the study of this environment or specific parts or aspects of it.
A number of human activities are conducted in the more accessible parts of the underwater environment. These include research, underwater diving for work or recreation, and underwater warfare with submarines. It is hostile to humans in many ways and often inaccessible, and therefore relatively little explored.
Extent[edit] The world ocean is the most visible part of Earth from space.Three quarters of the planet Earth are covered by water. Most of the planet's solid surface is abyssal plain, at depths between 4,000 and 5,500 metres (13,100 and 18,000 ft) below the surface of the oceans. The solid surface location on the planet closest to the center of the geoid is the Challenger Deep, located in the Mariana Trench at a depth of 10,924 metres (35,840 ft). There is a smaller part of the surface covered by bodies of fresh water and a large volume of underground water in aquifers. The underwater environment is hostile to humans in many ways and therefore little explored. It can be mapped by sonar, or more directly explored via manned, remotely operated, or autonomous submersibles. The ocean floors he been surveyed via sonar to at least a coarse resolution; particularly-strategic areas he been mapped in detail, to assist in nigating and detecting submarines, though the resulting maps may be classified.[citation needed]
Oceans and seas[edit] Main articles: Ocean and Sea Clouds over the Atlantic OceanAn ocean is a body of water that composes much of a planet's hydrosphere.[1] On Earth, an ocean is one of the major conventional divisions of the World Ocean. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern (Antarctic), and Arctic Oceans.[2][3] The word "ocean" is often used interchangeably with "sea" in American English. Strictly speaking, a sea is a body of water (generally a division of the world ocean) partly or fully enclosed by land,[4] though "the sea" refers also to the oceans.
Saline water covers approximately 361,000,000 km2 (139,000,000 sq mi) and is customarily divided into several principal oceans and smaller seas, with the ocean covering approximately 71% of Earth's surface and 90% of the Earth's biosphere.[5] The ocean contains 97% of Earth's water, and oceanographers he stated that less than 100% of the World Ocean has been explored.[5] The total volume is approximately 1.35 billion cubic kilometers (320 million cu mi) with an erage depth of nearly 3,700 meters (12,100 ft).[6][7][8]
Lakes, ponds, and rivers[edit] Main articles: Lake, Pond, and River Samur River in Azerbaijan – In the natural landscapeA lake is an area filled with water, localized in a basin, that is surrounded by land, apart from any river or other outlet that serves to feed or drain the lake.[9] Lakes lie on land and are not part of the ocean, and therefore are distinct from lagoons, and are also larger and deeper than ponds, though there are no official or scientific definitions.[10] Lakes can be contrasted with rivers or streams, which are usually flowing. Most lakes are fed and drained by rivers and streams. Natural lakes are generally found in mountainous areas, rift zones, and areas with ongoing glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers. In some parts of the world, there are many lakes because of chaotic drainage patterns left over from the last ice age. All lakes are temporary over geologic time scales, as they will slowly fill in with sediments or spill out of the basin containing them. Many lakes are artificial and are constructed for industrial or agricultural use, for hydro-electric power generation or domestic water supply, or for aesthetic, recreational purposes, or other activities.
A pond is an area filled with water, either natural or artificial, that is smaller than a lake.[11] It may arise naturally in floodplains as part of a river system, or be a somewhat isolated depression (such as a kettle, vernal pool, or prairie pothole). It may contain shallow water with marsh and aquatic plants and animals.[12] Ponds are frequently man-made or expanded beyond their original depth and bounds. Among their many uses, ponds provide water for agriculture and livestock, aid in habitat restoration, serve as fish hatcheries, are components of landscape architecture, may store thermal energy as solar ponds, and treat wastewater as treatment ponds. Ponds may be fresh, saltwater, or brackish.
A river is a natural flowing watercourse, usually freshwater, flowing under the influence of grity on ocean, lake, another river, or into the ground. Small rivers can be referred to using names such as stream, creek, brook, rivulet, and rill. There are no official definitions for the generic term river as applied to geographic features,[13] Rivers are part of the hydrological cycle; water generally collects in a river from precipitation in a drainage basin from surface runoff and other sources such as groundwater recharge, springs, and the release of stored water in natural ice and snow. Potamology is the scientific study of rivers, while limnology is the study of inland waters in general.
Subterranean water[edit] Main article: Aquifer Typical aquifer cross-section Diving in a flooded ceAn aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (grel, sand, or silt). The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. If an impermeable layer overlies the aquifer, pressure could cause it to become a confined aquifer.
Aquifers may be classified as porous or karst, where a porous aquifer contains the water in the spaces between the grains of a loose sediment or rock (typically sand or sandstone), while a karst aquifer contains water mainly in relatively large voids in relatively impermeable rock, such as limestone or dolomite.[14]
Water filled ces can be classified as active and relict: active ces he water flowing through them; relict ces do not, though water may be retained in them. Types of active ces include inflow ces ("into which a stream sinks"), outflow ces ("from which a stream emerges"), and through ces ("trersed by a stream").[15]
Artificial bodies of water[edit] Main articles: Dam, Reservoir, and CanalA reservoir is, most commonly, an enlarged natural or artificial lake, pond or impoundment created using a dam or lock to store water. Reservoirs can be created in a number of ways, including controlling a watercourse that drains an existing body of water, interrupting a watercourse to form an embayment within it, through excation, or building retaining walls or levees. Canals are artificial waterways which may he dams and locks that create reservoirs of low speed current flow.
Physical characteristics[edit] Main articles: Water and Properties of waterWater is a transparent, tasteless, odorless, and nearly colorless chemical substance. Its chemical formula is H2O, meaning that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. Water is the name of the liquid state of H2O at standard ambient temperature and pressure. Water at the surface of the Earth moves continually through the water cycle of evaporation, transpiration (evapotranspiration), condensation, precipitation, and runoff, usually reaching the sea. Water seldom exists in a pure form, it almost always contains dissolved substances, and usually other matter in suspension.
Density[edit] See also: Properties of water § Water, ice and vapor Density of ice and water as a function of temperatureThe density of water is about 1 gram per cubic centimetre (62 lb/cu ft) The density varies with temperature, but not linearly: as the temperature increases, the density rises to a peak at 3.98 °C (39.16 °F) and then decreases; this is unusual.[16] Regular, hexagonal ice is also less dense than liquid water—upon freezing, the density of water decreases by about 9%.[17] These effects are due to the reduction of thermal motion with cooling, which allows water molecules to form more hydrogen bonds that prevent the molecules from coming close to each other.[16] While below 4 °C the breakage of hydrogen bonds due to heating allows water molecules to pack closer despite the increase in the thermal motion (which tends to expand a liquid), above 4 °C water expands as the temperature increases.[16] Water near the boiling point is about 4% less dense than water at 4 °C (39 °F).[17][a]
Temperature distribution in a lake in summer and winterThe unusual density curve and lower density of ice than of water is vital to life—if water were most dense at the freezing point, then in winter the very cold water at the surface of lakes and other water bodies would sink, the lake could freeze from the bottom up, and all life in them would be killed.[17] Furthermore, given that water is a good thermal insulator (due to its heat capacity), some frozen lakes might not completely thaw in summer.[17] The layer of ice that floats on top insulates the water below.[18] Water at about 4 °C (39 °F) also sinks to the bottom, thus keeping the temperature of the water at the bottom constant (see diagram).[17]
The density of sea water depends on the dissolved salt content as well as the temperature. Ice still floats in the oceans, otherwise they would freeze from the bottom up. The salt content lowers the freezing point by about 1.9 °C and lowers the temperature of the density maximum of water to the fresh water freezing point at 0 °C.[19] This is why, in ocean water, the downward convection of colder water is not blocked by an expansion of water as it becomes colder near the freezing point. The oceans' cold water near the freezing point continues to sink. So creatures that live at the bottom of cold oceans like the Arctic Ocean generally live in water 4 °C colder than at the bottom of frozen-over fresh water lakes and rivers.
As the surface of sea water begins to freeze (at −1.9 °C for salinity 3.5%) the ice that forms is essentially salt-free, with about the same density as freshwater ice.[19] This ice floats on the surface, and the salt that is "frozen out" adds to the salinity and density of the sea water just below it, in a process known as brine rejection. This denser salt water sinks by convection. This produces essentially freshwater ice at −1.9 °C on the surface.[19] On a large scale, the process of brine rejection and sinking cold salty water results in ocean currents forming to transport such water away from the Poles, leading to a global system of currents called the thermohaline circulation.
Pressure[edit] See also: Hydrostatic pressureThe density of water causes ambient pressures that increase dramatically with depth. The atmospheric pressure at the surface is 14.7 pounds per square inch or around 100 kPa. A comparable hydrostatic pressure occurs at a depth of only 10 metres (33 ft) (9.8 metres (32 ft) for sea water). Thus, at about 10 m below the surface, the water exerts twice the pressure (2 atmospheres or 200 kPa) as air at surface level.
Buoyancy[edit] Main article: BuoyancyAny object immersed in water is subjected to a buoyant force that counters the force of grity, appearing to make the object less hey. If the overall density of the object exceeds the density of water, the object sinks. If the overall density is less than the density of water, the object rises until it floats on the surface.
Penetration of light[edit] Note the bluish cast given to objects in this underwater photo of pillow la (NOAA). See also: Underwater vision § VisibilityWith increasing depth underwater, sunlight is absorbed, and the amount of visible light diminishes. Because absorption is greater for long welengths (red end of the visible spectrum) than for short welengths (blue end of the visible spectrum), the colour spectrum is rapidly altered with increasing depth. White objects at the surface appear bluish underwater, and red objects appear dark, even black. Although light penetration will be less if water is turbid, in the very clear water of the open ocean less than 25% of the surface light reaches a depth of 10 m (33 feet). At 100 m (330 ft) the light present from the sun is normally about 0.5% of that at the surface.[citation needed]
The euphotic depth is the depth at which light intensity falls to 1% of the value at the surface. This depth is dependent upon water clarity, being only a few metres underwater in a turbid estuary, but may reach up to 200 metres in the open ocean. At the euphotic depth, plants (such as phytoplankton) he no net energy gain from photosynthesis and thus cannot grow.
Temperature[edit]There are three layers of ocean temperature: the surface layer, the thermocline, and the deep ocean. The erage temperature of surface layer is about 17 °C. About 90% of ocean's water is below the thermocline in the deep ocean, where most of the water is below 4 °C.[20]
There are temperature anomalies at active volcanic sites and hydrothermal vents, where deep-water temperatures can significantly exceed 100 °C.
Thermal conductivity[edit]Water conducts heat around 25 times more efficiently than air. Hypothermia, a potentially fatal condition, occurs when the human body's core temperature falls below 35 °C. Insulating the body's warmth from water is the main purpose of diving suits and exposure suits when used in water temperatures below 25 °C.
Acoustic properties[edit] See also: Underwater acousticsSound is transmitted about 4.3 times faster in water (1,484 m/s in fresh water) than in air (343 m/s). The human brain can determine the direction of sound in air by detecting small differences in the time it takes for sound wes in air to reach each of the two ears. For these reasons, divers find it difficult to determine the direction of sound underwater. Some animals he adapted to this difference and many use sound to nigate underwater.
Ecosystems[edit] Main articles: Aquatic ecosystem, Freshwater ecosystem, and Marine ecosystemAn aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems.[21]
Marine ecosystems are the largest of Earth's aquatic ecosystems and are distinguished by waters that he a high salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply[22][23] and 90% of habitable space on Earth.[24] Marine ecosystems include nearshore systems, such as the salt marshes, mudflats, seagrass meadows, mangroves, rocky intertidal systems and coral reefs. They also extend from the coast to include offshore systems, such as the surface ocean, pelagic ocean waters, the deep sea, oceanic hydrothermal vents, and the sea floor. Marine ecosystems are characterized by the biological community of organisms that they are associated with and their physical environment. As the world ocean is the principal component of Earth's hydrosphere, it is integral to life, forms part of the carbon cycle, and influences climate and weather patterns. The World Ocean is the habitat of 230,000 known species, but because much of it is unexplored, the number of species that exist in the ocean is much larger, possibly over two million.[25]
Freshwater ecosystems include lakes and ponds, rivers, streams, springs, aquifers, bogs, and wetlands. They he a lower salt content than marine ecosystems. Freshwater habitats can be classified by different factors, including temperature, light penetration, nutrients, and vegetation. Freshwater ecosystems can be divided into lentic ecosystems (still water) and lotic ecosystems (flowing water).[26]
Aquatic ecosystems are characterised by the limitation on ambient lighting due to absorption by the water itself and by dissolved and suspended matter in the water column, and by the support provided by buoyancy. Nutrients usable by plants are dissolved in the water, making them easily ailable. However, the interaction of light absorption by water, matter and living organisms themselves leads to very different light and light spectrum conditions depending on the respective ecosystem and its water depth. This affects photosynthesis and the ecology of plants and phytoplankton.[27] Outside the euphotic zone, photosynthesis cannot occur and life must use other sources of energy than sunlight.
Humans[edit] Main articles: Underwater diving and Science of underwater divingAlthough a number of human activities are conducted underwater—such as research, underwater diving for work or recreation, and underwater warfare with submarines, the underwater environment is hostile to humans in many ways and therefore little explored.
An immediate obstacle to human activity under water is that human lungs cannot naturally function in this environment. Unlike the gills of fish, human lungs are adapted to the exchange of gases at atmospheric pressure. Any penetration into the underwater environment for more than a few minutes requires artificial aids to maintain life.
For solid and liquid tissues like bone, muscle and blood, the high ambient pressure is not much of a problem; but it is a problem for any gas-filled spaces like the mouth, ears, paranasal sinuses and lungs. This is because the gas in those spaces is much more compressible than the solids and liquids, and reduces in volume much more when under pressure and so does not provide those spaces with support against the higher outside pressure. Even at a depth of 8 ft (2.4 m) underwater, an inability to equalize air pressure in the middle ear with outside water pressure can cause pain, and the tympanic membrane (eardrum) can rupture at depths under 10 ft (3 m). The danger of pressure damage is greatest in shallow water because the ratio of pressure change is greatest near the surface of the water. The raised pressure also affects the solution of breathing gases in the tissues over time, and can lead to a range of adverse effects, such as inert gas narcosis, and oxygen toxicity. Decompression must be controlled to oid bubble formation in the tissues and the consequent symptoms of decompression sickness.
With a few exceptions, the underwater environment tends to cool the unprotected human body. This heat loss will generally lead to hypothermia eventually.
Hazards[edit] See also: Hazard, List of diving hazards and precautions, Human factors in diving safety, and List of diving environments by hazardThere are several classes of hazards to humans inherent to the underwater environment.
Absence of breathable gas, which can cause asphyxia, specifically by drowning. Ambient pressures which could cause barotrauma, or toxic effects of breathing gas components at raised partial pressures. Ambient temperatures which may lead to hypothermia, or in unusual cases, to hyperthermia, due to high rates of heat exchange. Solution of inert breathing gas components may lead to decompression sickness if decompression is too rapid. Entrainment of diver by moving water in currents and wes can cause injury by impacting the diver against hard objects or moving them to inappropriate depths. Dangerous aquatic organisms of various sorts. Ambient pressure diving[edit] See also: Underwater diving and Underwater habitat Tektite I underwater habitat with ambient pressure divers using scubaIn ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold, or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep dives. Immersion in water and exposure to cold water and high pressure he physiological effects on the diver which limit the depths and duration possible in ambient pressure diving. Breath-hold endurance is a severe limitation, and breathing at high ambient pressure adds further complications, both directly and indirectly. Technological solutions he been developed which can greatly extend depth and duration of human ambient pressure dives, and allow useful work to be done underwater.[28]
Atmospheric pressure diving[edit] Main article: Atmospheric diving suit The Newtsuit has fully articulated, rotary joints in the arms and legs. These provide great mobility, while remaining largely unaffected by high pressures.A diver can be isolated from the ambient pressure by using an atmospheric diving suit (ADS), which is a small one-person articulated anthropomorphic submersible which resembles a suit of armour, with elaborate pressure resisting joints to allow articulation while maintaining an internal pressure of one atmosphere. An ADS can be used for relatively deep dives of up to 2,300 feet (700 m) for many hours, and eliminates the majority of significant physiological dangers associated with deep diving; the occupant need not decompress, there is no need for special gas mixtures, nor is there danger of decompression sickness or nitrogen narcosis, and the diver is effectively isolated from most aquatic organisms.[29] Divers do not even need to be skilled swimmers, but mobility and dexterity are significantly degraded.
Submersibles and submarines[edit] Main articles: Submersible and SubmarineA submersible is a small watercraft designed to operate underwater. The term submersible is often used to differentiate from other underwater vessels known as submarines, in that a submarine is a fully autonomous craft, capable of renewing its own power and breathing air, whereas a submersible is usually supported by a surface vessel, platform, shore team or sometimes a larger submarine. There are many types of submersibles, including both manned and unmanned craft, otherwise known as remotely operated vehicles or ROVs.[30]
Remotely operated or autonomous vehicles[edit] See also: Remotely operated underwater vehicle and Autonomous underwater vehicle ROV working on a subsea structure Pluto Plus AUV for underwater mine identification and destruction. From Norwegian minehunter KNM HinnøyRemotely operated underwater vehicles and autonomous underwater vehicles are part of a larger group of undersea systems known as unmanned underwater vehicles. ROVs are unoccupied, usually highly maneuverable, and operated by a crew either aboard a vessel/floating platform or on proximate land. They are linked to a host ship by a neutrally buoyant tether, or a load-carrying umbilical cable is used along with a tether management system (TMS). The umbilical cable contains a group of electrical conductors and fiber optics that carry electric power, video, and data signals between the operator and the TMS. Where used, the TMS then relays the signals and power for the ROV down the tether cable. Once at the ROV, the electric power is distributed between the components of the ROV. In high-power applications, most of the electric power drives a high-power electric motor which drives a hydraulic pump for propulsion and to power equipment. Most ROVs are equipped with at least a video camera and lights. Additional equipment is commonly added to expand the vehicle's capabilities. Autonomous underwater vehicles (AUVs) are robots that trel underwater without requiring input from an operator. Underwater gliders are a subclass of AUVs.[31]
Sciences[edit] Hydrology – Science of the movement, distribution, and quality of water on Earth Hydrography – Measurement of bodies of water Limnology – Science of inland aquatic ecosystems Marine biology – Scientific study of ocean life Marine chemistry – Chemistry of oceans and seas Marine ecology – The study of the interactions between organisms and environment in the sea Marine geology – Study of the history and structure of the ocean floor Oceanography – Scientific study of the ocean Potamology – Study of rivers Underwater archaeology – Study of human activity via evidence found underwater See also[edit] Science of underwater diving – Scientific concepts that are closely associated with underwater diving Subsurface ocean current – Oceanic currents that flow beneath surface currents Timeline of diving technology – Chronological list of notable events in the history of underwater diving equipment Underwater acoustics – Study of the propagation of sound in water Underwater photography – Genre of photography Underwater vision – Ability to see objects underwater UNESCO Convention on the Protection of the Underwater Cultural Heritage – Treaty adopted on 2 November 2001 References[edit] ^ "WordNet Search — ocean". Princeton University. Retrieved 21 February 2012. ^ "ocean, n". Oxford English Dictionary. Retrieved 5 February 2012. ^ "ocean". Merriam-Webster. Retrieved 6 February 2012. ^ "WordNet Search — sea". Princeton University. Retrieved 21 February 2012. ^ a b "NOAA – National Oceanic and Atmospheric Administration – Ocean". Noaa.gov. Retrieved 8 November 2012. ^ Qadri, Syed (2003). "Volume of Earth's Oceans". The Physics Factbook. Retrieved 7 June 2007. ^ Charette, Matthew; Smith, Walter H. F. (2010). "The volume of Earth's ocean". Oceanography. 23 (2): 112–114. doi:10.5670/oceanog.2010.51. hdl:1912/3862. ^ "Volumes of the World's Oceans from ETOPO1". NOAA. Archived from the original on 11 March 2015. Retrieved 7 March 2015.{{cite web}}: CS1 maint: bot: original URL status unknown (link) ^ Purcell, Adam. "Lakes". Basic Biology. ^ "Dictionary.com definition". Retrieved 25 June 2008. ^ "Definition of POND". www.merriam-webster.com. 21 August 2023. ^ John Clegg (1986). The New Observer's Book of Pond Life. Frederick Warne. p. 460. ISBN 978-0-7232-3338-1. ^ "GNIS FAQ". United States Geological Survey. Retrieved 26 January 2012. ^ "aquifer | Types & Facts". Encyclopedia Britannica. Retrieved 28 June 2021. ^ Silvestru, Emil (2008). The Ce Book. New Leaf. p. 38. ISBN 978-0-89051-496-2. ^ a b c Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 625. ISBN 978-0-08-037941-8. ^ a b c d e Perlman, Howard. "Water Density". The USGS Water Science School. Retrieved 3 June 2016. ^ Zumdahl, Steven S.; Zumdahl, Susan A. (2013). Chemistry (9th ed.). Cengage Learning. p. 493. ISBN 978-1-13-361109-7. ^ a b c "Can the ocean freeze?". National Ocean Service. National Oceanic and Atmospheric Administration. Retrieved 9 June 2016. ^ "Temperature of Ocean Water". Windows to the Universe. National Earth Science Teachers Association (NESTA). ^ Alexander, Did E. (1 May 1999). Encyclopedia of Environmental Science. Springer. ISBN 0-412-74050-8. ^ "Oceanic Institute". www.oceanicinstitute.org. Archived from the original on 3 January 2019. Retrieved 1 December 2018. ^ "Ocean Habitats and Information". 5 January 2017. Archived from the original on 1 April 2017. Retrieved 1 December 2018. ^ "Facts and figures on marine biodiversity | United Nations Educational, Scientific and Cultural Organization". www.unesco.org. Retrieved 1 December 2018. ^ Drogin, Bob (2 August 2009). "Mapping an ocean of species". Los Angeles Times. Retrieved 18 August 2009. ^ Wetzel, Robert G. (2001). Limnology: lake and river ecosystems (3rd ed.). San Diego: Academic Press. ISBN 978-0-12-744760-5. OCLC 46393244. ^ Hintz, Nils Hendrik; Schulze, Brian; Wacker, Alexander; Striebel, Maren (March 2022). "Ecological impacts of photosynthetic light harvesting in changing aquatic environments: A systematic literature map". Ecology and Evolution. 12 (3) e8753. Bibcode:2022EcoEv..12E8753H. doi:10.1002/ece3.8753. ISSN 2045-7758. PMC 8939368. PMID 35356568. ^ Kot, Jacek (2011). Educational and Training Standards for Physicians in Diving and Hyperbaric Medicine (PDF). Kiel, Germany: Joint Educational Subcommittee of the European Committee for Hyperbaric Medicine (ECHM) and the European Diving Technical Committee (EDTC). ^ "WASP Specifications" (PDF). Archived from the original (PDF) on 3 March 2014. Retrieved 27 February 2014. ^ "Submersible". The Canadian Encyclopedia. 2011. Archived from the original on 4 December 2017. Retrieved 9 August 2019.. The Canadian Encyclopedia. F.J. Chambers 02/07/2006 "Cyrus Albert Birge - the Canadian Encyclopedia". Archived from the original on 15 March 2012. Retrieved 20 October 2011.{{cite web}}: CS1 maint: bot: original URL status unknown (link) ^ "Remotely Operated Vehicle Design and Function". Maritime About. Archived from the original on 1 July 2016. Retrieved 4 June 2016. Footnotes[edit] ^ (1-0.95865/1.00000) × 100% = 4.135% vteUnderwater diving Diving activities Diving modes Atmospheric pressure diving Freediving Saturation diving Scuba diving Snorkeling Surface oriented diving Surface-supplied diving Unmanned diving Diving equipment Cleaning and disinfection of personal diving equipment Human factors in diving equipment design List of diving equipment manufacturers Basic equipment Diving mask Snorkel Swimfin Breathing gas Bailout gas Bottom gas Breathing air Decompression gas Emergency gas supply Heliox Hydreliox Hydrox Nitrox Oxygen Trel gas Trimix Buoyancy andtrim equipment Avelo diving system Buoyancy compensator Power inflator Dump valve Variable buoyancy pressure vessel Diving weighting system Ankle weights Integrated weights Trim weights Weight belt Decompressionequipment Decompression buoy Decompression chamber Decompression cylinder Decompression tables Decompression trapeze Dive computer Diving bell Diving shot Diving stage Jersey upline Jonline Diving suit Atmospheric diving suit JIM suit Newtsuit Dry suit Sladen suit Standard diving suit Rash vest Wetsuit Dive skins Hot-water suit Helmetsand masks Anti-fog Diving helmet Free-flow helmet Lightweight demand helmet Orinasal mask Reclaim helmet Shallow water helmet Standard diving helmet Diving mask Band mask Full-face diving mask Half mask Instrumentation Bottom timer Depth gauge Dive computer Dive timer Diving watch Helium release valve Electro-galvanic oxygen sensor Pneumofathometer Submersible pressure gauge Mobilityequipment Diver propulsion vehicle Human torpedo Wet sub Diving bell Closed bell Wet bell Diving stage Swimfin Monofin PowerSwim Towboard Safetyequipment Alternative air source Octopus regulator Pony bottle Bolt snap Buddy line Dive light Diver's cutting tool Diver's knife Diver's telephone Through-water communications Underwater acoustic communication Diving bell Diving safety harness Emergency gas supply Bailout block Bailout bottle Lifeline Screw gate carabiner Emergency locator beacon Rescue tether Safety helmet Shark-proof cage Snoopy loop Nigation equipment Distance line Diving compass Dive reel Line marker Surface marker buoy Silt screw Underwaterbreathingapparatus Atmospheric diving suit Diving cylinder Burst disc Scuba cylinder valve Diving helmet Reclaim helmet Diving regulator Mechanism of diving regulators Regulator malfunction Regulator freeze Single-hose regulator Twin-hose regulator Full-face diving mask Open-circuitscuba Scuba set Bailout bottle Decompression cylinder Independent doubles Manifolded twin set Scuba manifold Pony bottle Scuba configuration Sidemount Sling cylinder Diving rebreathers Carbon dioxide scrubber Carleton CDBA Clearance Divers Life Support Equipment Cryogenic rebreather CUMA DSEA Dolphin Halcyon PVR-BASC Halcyon RB80 IDA71 Interspiro DCSC LAR-5 LAR-6 LAR-V LARU Mark IV Amphibian Porpoise Ray Siebe Gorman CDBA Salvus Siva Surface-supplieddiving equipment Air line Diver's umbilical Diving air compressor Gas panel Hookah Scuba replacement Snuba Standard diving dress Divingequipmentmanufacturers AP Diving Apeks Aqua Lung America Aqua Lung/La Spirotechnique Beuchat René Calero Cis-Lunar Cressi-Sub Dacor DESCO Dive Xtras Divex Diving Unlimited International Drägerwerk Faber Fenzy Maurice Fernez Technisub Oscar Gugen Heinke HeinrichsWeikamp Johnson Outdoors Mares Morse Diving Nemrod Oceanic Worldwide Porpoise Shearwater Research Siebe Gorman Submarine Products Suunto Diving support equipmentAccess equipment Boarding stirrup Diver lift Diving bell Diving ladder Diving platform (scuba) Diving stage Downline Jackstay Launch and recovery system Messenger line Moon pool Breathing gashandling Air filtration Activated carbon Hopcalite Molecular sieve Silica gel Booster pump Carbon dioxide scrubber Cascade filling system Diver's pump Diving air compressor Diving air filter Water separator High pressure breathing air compressor Low pressure breathing air compressor Gas blending Gas blending for scuba diving Gas panel Gas reclaim system Gas storage bank Gas storage quad Gas storage tube Helium analyzer Nitrox production Membrane gas separation Pressure swing adsorption Oxygen analyser Electro-galvanic oxygen sensor Oxygen compatibility Decompressionequipment Air-lock Built-in breathing system Decompression tables Diving bell Bell cursor Closed bell Clump weight Launch and recovery system Wet bell Diving chamber Diving stage Recreational Dive Planner Saturation diving system Platforms Dive boat Canoe and kayak diving Combat rubber raiding craft Liveaboard Subskimmer Diving support vessel HMS Challenger (K07) Underwaterhabitat Aquarius Reef Base Continental Shelf Station Two Helgoland Habitat Scott Carpenter Space Analog Station SEALAB Tektite habitat Remotely operatedunderwater vehicles 8A4-class ROUV ABISMO Atlantis ROV Team COTSBot CURV Deep Drone Épaulard Global Explorer ROV Goldfish-class ROUV Kaikō ROV Kaşif ROUV Long-Term Mine Reconnaissance System Mini Rover ROV OpenROV ROV KIEL 6000 ROV PHOCA Scorpio ROV Sea Dragon-class ROV Seabed tractor Seafox drone SeaPerch SJT-class ROUV T1200 Trenching Unit VideoRay UROVs Safety equipment Diver down flag Diving shot ENOS Rescue-System Hyperbaric lifeboat Hyperbaric stretcher Jackstay Jonline Reserve gas supply General Diving spread Air spread Saturation spread Hot water system Sonar Underwater acoustic positioning system Underwater acoustic communication FreedivingActivities Aquathlon Apnoea finswimming Freediving Haenyeo Pearl hunting Ama Snorkeling Spearfishing Underwater football Underwater hockey Underwater rugby Underwater target shooting Competitions Nordic Deep Vertical Blue Disciplines Constant weight (CWT) Constant weight bi-fins (CWTB) Constant weight without fins (CNF) Dynamic apnea (DYN) Dynamic apnea without fins (DNF) Free immersion (FIM) No-limits apnea (NLT) Static apnea (STA) Skandalopetra diving Variable weight apnea (VWT) Variable weight apnea without fins Equipment Diving mask Diving suit Hawaiian sling Polespear Snorkel (swimming) Speargun Swimfins Monofin Water polo cap Freedivers Deborah Andollo Simone Arrigoni Peppo Biscarini Michael Board Sara Campbell Derya Can Göçen Goran Čolak Carlos Coste Robert Croft Mandy-Rae Cruickshank Yasemin Dalkılıç Leonardo D'Imporzano Flia Eberhard Şahika Ercümen Emma Farrell Francisco Ferreras Pierre Frolla Flia Eberhard Mehgan Heaney-Grier Elisabeth Kristoffersen Andriy Yevhenovych Khvetkevych Loïc Leferme Enzo Maiorca Jacques Mayol Audrey Mestre Karol Meyer Kate Middleton Stéphane Mifsud Alexey Molchanov Natalia Molchanova De Mullins Patrick Musimu Guillaume Néry Herbert Nitsch Umberto Pelizzari Liv Philip Annelie Pompe Stig Severinsen Tom Sietas Martin Štěpánek Walter Steyn Tanya Streeter William Trubridge Devrim Cenk Ulusoy Fatma Uruk Danai Varveri Alessia Zecchini Nataliia Zharkova Kateryna Sadurska Hazards Barotrauma Drowning Freediving blackout Deep-water blackout Shallow-water blackout Hypercapnia Hypothermia Historical Ama Octopus wrestling Swimming at the 1900 Summer Olympics – Men's underwater swimming Organisations AIDA International Scuba Schools International Australian Underwater Federation British Freediving Association Confédération Mondiale des Activités Subaquatiques Fédération Française d'Études et de Sports Sous-Marins Performance Freediving International Professional divingOccupations Ama Commercial diver Commercial offshore diver Hazmat diver Divemaster Diving instructor Diving safety officer Diving superintendent Diving supervisor Haenyeo Media diver Police diver Public safety diver Scientific diver Underwater archaeologist Militarydiving Army engineer diver Canadian Armed Forces Divers Clearance diver Frogman Minentaucher Royal Ny ships diver United States military divers U.S. Ny diver U.S.Ny master diver Militarydivingunits 7th Marine Brigade Clearance Diving Branch (RAN) Commando Hubert Combat Divers Service (Lithuania) Comando Raggruppamento Subacquei e Incursori Teseo Tesei Decima Flottiglia MAS Frogman Corps (Denmark) Fuerzas Especiales Fukuryu GRUMEC Grup Gerak Khas Jagdkommando JW Formoza JW GROM JW Komandosów Kommando Spezialkräfte Marine KOPASKA MARCOS Marine Commandos Marinejegerkommandoen Marine Raider Regiment Minedykkerkommandoen Namibian Marine Corps Operational Diving Unit Nal Diving Unit (Singapore) Nal Service Diving Section Nal Special Operations Command Operational Diving Division (SA Ny) Royal Engineers Russian commando frogmen Sappers Divers Group Shayetet 13 Special Air Service Special Air Service Regiment Special Actions Detachment Special Boat Service Special Boat Squadron (Sri Lanka) Special Forces Command (Turkey) Special Forces Group (Belgium) Special Operations Battalion (Croatia) Special Service Group (Ny) Special Warfare Diving and Salvage Tactical Divers Group US Marine Corps Force Reconnaissance US Marine Corps Reconnaissance Battalions US Ny SEALs Underwater Construction Teams Underwater Demolition Command Underwater Demolition Team Underwater Offence (Turkish Armed Forces) UNGERIN Underwaterwork Commercial offshore diving Dive leader Diver training Recreational diver training Hazmat diving Hyperbaric welding Marine construction Offshore construction Underwater construction Media diving Pearl hunting Police diving Potable water diving Public safety diving Scientific diving Ships husbandry Sponge diving Submarine pipeline Underwater archaeology Archaeology of shipwrecks Underwater cutting and welding Underwater demolition Underwater inspection Nondestructive testing Underwater logging Underwater photography Underwater search and recovery Underwater searches Underwater videography Underwater survey Salvage diving SS Egypt Kronan La Belle SS Laurentic RMS Lusitania Mars Mary Rose USS Monitor HMS Royal George Vasa Divingcontractors COMEX Helix Energy Solutions Group International Marine Contractors Association Tools andequipment Abrasive waterjet Airlift Baited remote underwater video In-water surface cleaning Brush cart Citation cleaning Pressure washing Pigging Hot stab Lifting bag Remotely operated underwater vehicle Thermal lance Tremie Water jetting Underwaterweapons Limpet mine Speargun Hawaiian sling Polespear Underwaterfirearm Gyrojet Mk 1 Underwater Defense Gun Powerhead Underwater pistols Heckler & Koch P11 SPP-1 underwater pistol Underwater revolvers AAI underwater revolver Underwater rifles ADS amphibious rifle APS underwater rifle ASM-DT amphibious rifle QBS-06 Recreational diving Recreational dive sites Index of recreational dive sites List of wreck diving sites Outline of recreational dive sites Children in scuba diving Specialties Altitude diving Ce diving Deep diving Ice diving Muck diving Open-water diving Rebreather diving Sidemount diving Solo diving Technical diving Underwater photography Wreck diving Diverorganisations British Sub-Aqua Club (BSAC) Ce Divers Association of Australia (CDAA) Ce Diving Group (CDG) Comhairle Fo-Thuinn (CFT) Confédération Mondiale des Activités Subaquatiques (CMAS) Federación Española de Actividades Subacuáticas (FEDAS) Fédération Française d'Études et de Sports Sous-Marins (FFESSM) International Association for Handicapped Divers (IAHD) Quintana Roo Speleological Survey (QRSS) Woodville Karst Plain Project (WKPP) Diving tourismindustry Dive center Diving in Timor-Leste Diving in the Maldives Environmental impact of recreational diving Scuba diving tourism Scuba diving in the Cayman Islands Shark tourism Sinking ships for wreck diving sites Underwater diving in Guam Diving eventsand festivals Diversnight Underwater Bike Race Diving safety Human factors in diving equipment design Human factors in diving safety Life-support system Safety-critical system Scuba diving fatalities Underwater diving emergency Water safety Water surface searches Divinghazards List of diving hazards and precautions Environmental Current Delta-P Entanglement hazard Overhead Silt out We action Equipment Freeflow Use of breathing equipment in an underwater environment Failure of diving equipment other than breathing apparatus Single point of failure Physiological Cold shock response Decompression Nitrogen narcosis Oxygen toxicity Seasickness Uncontrolled decompression Diver behiour and competence Incompetence Overconfidence effect Panic Task loading Trait anxiety Willful violation Consequences Barotrauma Decompression sickness Drowning Hypothermia Hypoxia Hypercapnia Hyperthermia Non-freezing cold injury Divingprocedures Ascending and descending Emergency ascent Boat diving Canoe and kayak diving Buddy diving buddy check Decompression Decompression practice Pyle stop Ratio decompression Dive briefing Dive log Dive planning Rule of thirds Scuba gas planning Diver communications Diver rescue Diver training Doing It Right Drift diving Gas blending for scuba diving Night diving Rebreather diving Scuba gas management Solo diving Wall diving Riskmanagement Checklist Hazard identification and risk assessment Hazard analysis Job safety analysis Risk assessment Hyperbaric evacuation and rescue Risk control Hierarchy of hazard controls Incident pit Lockout–tagout Permit To Work Redundancy Safety data sheet Situation awareness Diving team Bellman Chamber operator Diver medical technician Diver's attendant Diving supervisor Diving systems technician Gas man Life support technician Stand-by diver Equipmentsafety Breathing gas quality Testing and inspection of diving cylinders Hydrostatic test Sustained load cracking Diving regulator Breathing performance of regulators Occupationalsafety andhealth Association of Diving Contractors International International Marine Contractors Association Code of practice Contingency plan Diving regulations Emergency response plan Diving safety officer Diving superintendent Diving supervisor Operations manual Standard operating procedure Diving medicineDivingdisorders List of signs and symptoms of diving disorders Cramp Motion sickness Surfer's ear Pressurerelated Alternobaric vertigo Barostriction Barotrauma Air embolism Aerosinusitis Barodontalgia Dental barotrauma Middle ear barotrauma Pulmonary barotrauma Compression arthralgia Decompression illness Dysbarism Oxygen Freediving blackout Hyperoxia Hypoxia Oxygen toxicity Inert gases Avascular necrosis Decompression sickness Dysbaric osteonecrosis Inner ear decompression sickness Isobaric counterdiffusion Tarana High-pressure nervous syndrome Hydrogen narcosis Nitrogen narcosis Carbon dioxide Hypercapnia Hypocapnia Breathing gascontaminants Carbon monoxide poisoning Immersionrelated Asphyxia Drowning Hypothermia Immersion diuresis Instinctive drowning response Laryngospasm Salt water aspiration syndrome Swimming-induced pulmonary edema Treatment Demand valve oxygen therapy First aid Hyperbaric medicine Hyperbaric treatment schedules In-water recompression Oxygen therapy Therapeutic recompression Personnel Diving Medical Examiner Diving Medical Practitioner Diving Medical Technician Hyperbaric nursing Screening Atrial septal defect Effects of drugs on fitness to dive Fitness to dive Psychological fitness to dive ResearchResearchers indiving physiologyand medicine Arthur J. Bachrach Albert R. Behnke Peter B. Bennett Paul Bert George F. Bond Robert Boyle Alf O. Brubakk Albert A. Bühlmann John R. Clarke Guybon Chesney Castell Damant Kenneth William Donald William Paul Fife John Scott Haldane Robert William Hamilton Jr. Henry Valence Hempleman Leonard Erskine Hill Brian Andrew Hills Felix Hoppe-Seyler Christian J. Lambertsen Simon Mitchell Charles Momsen Neal W. Pollock John Rawlins Charles Wesley Shilling Edward D. Thalmann Jacques Triger Diving medicalresearchorganisations Aerospace Medical Association Divers Alert Network (DAN) Diving Diseases Research Centre (DDRC) Diving Medical Advisory Council (DMAC) European Diving Technology Committee (EDTC) European Underwater and Baromedical Society (EUBS) National Board of Diving and Hyperbaric Medical Technology Nal Submarine Medical Research Laboratory Royal Australian Ny School of Underwater Medicine Rubicon Foundation South Pacific Underwater Medicine Society (SPUMS) Undersea and Hyperbaric Medical Society (UHMS) United States Ny Experimental Diving Unit (NEDU) Law Civil liability in recreational diving Diving regulations Duty of care List of legislation regulating underwater diving Investigation of diving accidents Convention on the Protection of the Underwater Cultural Heritage History of underwater diving History of decompression research and development History of dive computers History of Diving Museum History of scuba diving List of researchers in underwater diving Lyons Maritime Museum Man in the Sea Museum Timeline of atmospheric diving suits Timeline of diving technology Pearling in Western Australia US Ny decompression models and tables Archeologicalsites SS Commodore USS Monitor Queen Anne's Revenge Whydah Gally Underwater artand artists The Diver Jason deCaires Taylor Engineersand inventors Jerónimo de Ayanz y Beaumont William Beebe Georges Beuchat Giovanni Alfonso Borelli Joseph-Martin Cabirol John R. Clarke Jacques Cousteau Charles Anthony Deane John Deane Louis de Corlieu Auguste Denayrouze Ted Eldred Henry Fleuss Émile Gagnan Karl Heinrich Klingert Peter Kreeft Christian J. Lambertsen Yves Le Prieur John Lethbridge Ernest William Moir Joseph Salim Peress Auguste Piccard Joe Soie Willard Franklyn Searle Gordon Smith Augustus Siebe Pierre-Marie Touboulic Jacques Triger Historicalequipment Aqua-Lung RV Calypso SP-350 Denise Magnesium torch Nikonos Porpoise regulator Standard diving dress Sub Marine Explorer Vintage scuba Diverpropulsionvehicles Advanced SEAL Delivery System Cosmos CE2F series Dry Combat Submersible Human torpedo Motorised Submersible Canoe Necker Nymph R-2 Mala-class swimmer delivery vehicle SEAL Delivery Vehicle Shallow Water Combat Submersible Siluro San Bartolomeo Welfreighter Wet Nellie Military andcovert operations Raid on Alexandria (1941) Sinking of the Rainbow Warrior Scientific projects 1992 cageless shark-diving expedition Mission 31 Awards and events Hans Hass Award International Scuba Diving Hall of Fame London Diving Chamber Dive Lectures NOGI Awards Women Divers Hall of Fame IncidentsDive boat incidents Sinking of MV Conception Diver rescues Alpazat ce rescue Tham Luang ce rescue Early diving John Day (carpenter) Charles Spalding Ebenezer Watson Freediving fatalities Stephen Keenan Loïc Leferme Audrey Mestre Nicholas Mevoli Natalia Molchanova Offshorediving incidents Byford Dolphin diving bell accident Drill Master diving accident Star Canopus diving accident Stena Seaspread diving accident Venture One diving accident Waage Drill II diving accident Wildrake diving accident Professionaldiving fatalities Roger Baldwin John Bennett Victor F. Guiel Jr. Francis P. Hammerberg Craig M. Hoffman Peter Henry Michael Holmes Johnson Sea Link accident Edwin Clayton Link Gerard Anthony Prangley Per Skipnes Robert John Smyth Albert D. Stover Richard A. Walker Lothar Michael Ward Joachim Wendler Bradley Westell Arne Zetterström Scuba divingfatalities 1973 Mount Gambier ce diving accident Ricardo Armbruster Allan Bridge Did Bright Berry L. Cannon Cotton Coulson Cláudio Coutinho E. Yale Dawson Deon Dreyer Milan Dufek Sheck Exley Maurice Fargues Fernando Garfella Palmer Guy Garman Steve Irwin death Jim Jones Henry Way Kendall Artur Kozłowski Yuri Lipski Kirsty MacColl Agnes Milowka François de Roubaix Chris and Chrissy Rouse De Shaw Wesley C. Skiles Dewey Smith Rob Stewart Esbjörn Svensson Josef Velek PublicationsManuals NOAA Diving Manual U.S. Ny Diving Manual Basic Ce Diving: A Blueprint for Survival Underwater Handbook Bennett and Elliott's physiology and medicine of diving Encyclopedia of Recreational Diving The new science of skin and scuba diving Professional Diver's Handbook Basic Scuba Standards andCodes of Practice Code of Practice for Scientific Diving (UNESCO) DIN 7876 IMCA Code of Practice for Offshore Diving ISO 24801 Recreational diving services — Requirements for the training of recreational scuba divers General non-fiction The Darkness Beckons Goldfinder The Last Dive Shadow Divers The Silent World: A Story of Undersea Discovery and Adventure Research List of Divers Alert Network publications Dive guides Training and registrationDivertraining Competence and assessment Competency-based learning Refresher training Skill assessment Diver training standard Diving instructor Diving school Occupational diver training Commercial diver training Military diver training Public safety diver training Scientific diver training Recreational diver training Introductory diving ISO training standards Teaching method Muscle memory Overlearning Stress exposure training Skills Combat sidestroke Diver nigation Diver trim Ear clearing Frenzel maneuver Valsalva maneuver Finning techniques Scuba skills Buddy breathing Low impact diving Diamond Reef System Surface-supplied diving skills Underwater searches RecreationalscubacertificationlevelsCore diving skills Advanced Open Water Diver Autonomous diver CMAS* scuba diver CMAS** scuba diver Introductory diving Low Impact Diver Master Scuba Diver Open Water Diver Supervised diver Leadership skills Dive leader Divemaster Diving instructor Master Instructor Specialist skills Rescue Diver Solo diver Diver trainingcertificationand registrationorganisations European Underwater Federation (EUF) International Diving Regulators and Certifiers Forum (IDRCF) International Diving Schools Association (IDSA) International Marine Contractors Association (IMCA) List of diver certification organizations National Oceanic and Atmospheric Administration (NOAA) Nautical Archaeology Society Recreational diver course referral World Recreational Scuba Training Council (WRSTC) Commercial divercertificationauthorities Australian Diver Accreditation Scheme (ADAS) Commercial diver registration in South Africa Divers Institute of Technology Health and Safety Executive (HSE) Department of Employment and Labour Commercial divingschools Divers Academy International Norwegian diver school Free-divingcertificationagencies AIDA International (AIDA) Confédération Mondiale des Activités Subaquatiques (CMAS) Performance Freediving International (PI) Scuba Schools International (SSI) Recreationalscubacertificationagencies American Canadian Underwater Certifications (ACUC) American Nitrox Divers International (ANDI) Association nationale des moniteurs de plongée (ANMP) British Sub-Aqua Club (BSAC) Comhairle Fo-Thuinn (CFT) Confédération Mondiale des Activités Subaquatiques (CMAS) Federación Española de Actividades Subacuáticas (FEDAS) Fédération Française d'Études et de Sports Sous-Marins (FFESSM) Federazione Italiana Attività Subacquee (FIAS) Global Underwater Explorers (GUE) International Association for Handicapped Divers (IAHD) International Association of Nitrox and Technical Divers (IANTD) International Life Sing Federation (ILS) Israeli Diving Federation (TIDF) National Academy of Scuba Educators (NASE) National Association of Underwater Instructors (NAUI) Nederlandse Onderwatersport Bond (NOB) Professional Association of Diving Instructors (PADI) Professional Diving Instructors Corporation (PDIC) Professional Technical and Recreational Diving (ProTec) Rebreather Association of International Divers (RAID) Sub-Aqua Association (SAA) Scuba Diving International (SDI) Scuba Educators International (SEI) Scuba Schools International (SSI) Türkiye Sualtı Sporları Federasyonu (TSSF) United Diving Instructors (UDI) YMCA SCUBA Program Scientific divercertificationauthorities American Academy of Underwater Sciences (AAUS) CMAS Scientific Committee Technical divercertificationagencies American Nitrox Divers International (ANDI) British Sub-Aqua Club (BSAC) Confédération Mondiale des Activités Subaquatiques (CMAS) Diving Science and Technology (DSAT) Federazione Italiana Attività Subacquee (FIAS) International Association of Nitrox and Technical Divers (IANTD) Professional Association of Diving Instructors (PADI) Professional Diving Instructors Corporation (PDIC) Professional Technical and Recreational Diving (ProTec) Rebreather Association of International Divers (RAID) Trimix Scuba Association (TSA) Cediving Ce Divers Association of Australia (CDAA) Ce Diving Group (CDG) Global Underwater Explorers (GUE) National Speleological Society#Ce Diving Group (CDG) National Association of Underwater Instructors (NAUI) Technical Diving International (TDI) Military divertraining centres Defence Diving School Ny Diving Salvage and Training Center Underwater Escape Training Unit Military divertraining courses United States Marine Corps Combatant Diver Course Underwater sportsSurface snorkeling Finswimming Snorkeling/breath-hold Spearfishing Underwater football Underwater hockey Australia Turkey Underwater rugby Colombia United States Underwater target shooting Breath-hold Aquathlon Apnoea finswimming Freediving Open Circuit Scuba Immersion finswimming Sport diving Underwater cycling Underwater orienteering Underwater photography Rebreather Underwater photography Sports governingorganisations and federations International AIDA International Confédération Mondiale des Activités Subaquatiques) National AIDA Hellas Australian Underwater Federation British Freediving Association British Octopush Association British Underwater Sports Association Comhairle Fo-Thuinn Federación Española de Actividades Subacuáticas Fédération Française d'Études et de Sports Sous-Marins South African Underwater Sports Federation Türkiye Sualtı Sporları Federasyonu Underwater Society of America) Competitions 14th CMAS Underwater Photography World Championship Underwater Hockey World Championships Underwater Orienteering World Championships Underwater Rugby World Championships Underwater diversPioneersof diving Eduard Admetlla i Lázaro Aquanaut Mary Bonnin Amelia Behrens-Furniss James F. Cahill Jacques Cousteau Billy Deans Dottie Frazier Trevor Hampton Hans Hass Hannes Keller Dick Rutkowski Teseo Tesei Arne Zetterström Underwaterscientistsarchaeologists andenvironmentalists Michael Arbuthnot Robert Ballard George Bass Mensun Bound Louis Boutan Jeffrey Bozanic Hugh Bradner Cathy Church Eugenie Clark James P. Delgado Sylvia Earle John Christopher Fine George R. Fischer Anders Franzén Honor Frost Fernando Garfella Palmer Did Gibbins Graham Jessop Swietenia Puspa Lestari Pilar Luna Robert F. Marx Anna Marguerite McCann Innes McCartney Charles T. Meide Mark M. Newell Lyuba Ognenova-Marinova John Peter Oleson Mendel L. Peterson Richard Pyle Andreas Rechnitzer William R. Royal Margaret Rule Gunter Schöbel Stephanie Schwabe Myriam Seco E. Lee Spence Robert Sténuit Peter Throckmorton Cristina Zenato Scuba recordholders Pascal Bernabé Jim Bowden Mark Ellyatt Sheck Exley Nuno Gomes Claudia Serpieri Krzysztof Starnawski Underwaterfilmmakersand presenters Samir Alhafith Did Attenborough Ramón Bro Jean-Michel Cousteau Richie Kohler Paul Rose Andy Torbet Ivan Tors Andrew Wight James Cameron Underwaterphotographers Doug Allan Tamara Benitez Georges Beuchat Adrian Biddle Jonathan Bird Eric Cheng Neville Coleman Jacques Cousteau John D. Craig Ben Cropp Bernard Delemotte Did Doubilet Candice Farmer John Christopher Fine Rodney Fox Ric Frazier Stephen Frink Peter Gimbel Monty Halls Hans Hass Henry Way Kendall Rudie Kuiter Joseph B. MacInnis Luis Marden Agnes Milowka Noel Monkman Pete Oxford Steve Parish Zale Parry Pierre Petit Leni Riefenstahl Peter Scoones Brian Skerry Wesley C. Skiles E. Lee Spence Philippe Tailliez Ron Taylor Valerie Taylor Albert Tillman John Veltri Stan Waterman Michele Westmorland John Ernest Williamson J. Lamar Worzel Underwaterexplorers Ces Graham Balcombe Sheck Exley Martyn Farr Jochen Hasenmayer Jill Heinerth Jarrod Jablonski Brian Kakuk William Hogarth Main Tom Mount Jack Sheppard Bill Stone Reefs Arthur C. Clarke Wrecks Leigh Bishop John Chatterton Clive Cussler Bill Nagle Valerie van Heest Aristotelis Zervoudis Aquanauts Andrew Abercromby Joseph M. Acaba Clayton Anderson Richard R. Arnold Serena Auñón-Chancellor Michael Barratt (astronaut) Robert A. Barth Robert L. Behnken Randolph Bresnik Timothy J. Broderick Justin Brown Berry L. Cannon Scott Carpenter Gregory Chamitoff Steve Chappell Catherine Coleman Robin Cook Craig B. Cooper Fabien Cousteau Philippe Cousteau Timothy Creamer Jonathan Dory Pedro Duque Sylvia Earle Jeanette Epps Sheck Exley Albert Falco Andrew J. Feustel Michael Fincke Satoshi Furukawa Ronald J. Garan Jr. Michael L. Gernhardt Christopher E. Gerty Did Gruber Chris Hadfield Jeremy Hansen José M. Hernández John Herrington Paul Hill Akihiko Hoshide Mark Hulsbeck Emma Hwang Norishige Kanai Les Kaufman Scott Kelly Karen Kohanowich Timothy Kopra Dominic Landucci Jon Lindbergh Kjell N. Lindgren Michael López-Alegría Joseph B. MacInnis Sandra Magnus Thomas Marshburn Matthias Maurer K. Megan McArthur Craig McKinley Jessica Meir Simone Melchior Dorothy Metcalf-Lindenburger Andreas Mogensen Karen Nyberg John D. Olivas Takuya Onishi Luca Parmitano Nicholas Patrick Tim Peake Thomas Pesquet Marc Reagan Garrett Reisman Kathleen Rubins Dick Rutkowski Tara Ruttley Did Saint-Jacques Josef Schmid Robert Sheats Dewey Smith Steve Squyres Heidemarie Stefanyshyn-Piper Robert Sténuit Hervé Stevenin Nicole Stott James Talacek Daniel M. Tani Robert Thirsk Bill Todd Mark T. Vande Hei Koichi Wakata Rex J. Walheim Shannon Walker John Morgan Wells Joachim Wendler Douglas H. Wheelock Peggy Whitson Dafydd Williams Jeffrey Williams Sunita Williams Reid Wiseman Kimiya Yui Writers and journalists Michael C. Barnette Victor Berge Philippe Diolé Gary Gentile Bret Gilliam Bob Halstead Hillary Hauser Trevor Jackson Steve Lewis John Mattera Rescuers Craig Challen Richard Harris Rick Stanton John Volanthen Frogmen Lionel Crabb Ian Edward Fraser Sydney Knowles James Joseph Magennis Commercial salvors Keith Jessop Science of underwater diving List of researchers in underwater diving Divingphysics Metre sea water Neutral buoyancy Underwater acoustics Modulated ultrasound Underwater vision Underwater computer vision Divingphysiology Blood shift Cold shock response Diving reflex Equivalent narcotic depth Maximum operating depth Physiological response to water immersion Thermal balance of the underwater diver Underwater vision Work of breathing Decompressiontheory Decompression models: Bühlmann decompression algorithm Haldane's decompression model Reduced gradient bubble model Thalmann algorithm Thermodynamic model of decompression Varying Permeability Model Equivalent air depth Oxygen window Physiology of decompression Divingenvironments Underwater exploration Deep-sea exploration Classification List of diving environments by type Altitude diving Benign water diving Confined water diving Deep diving Inland diving Inshore diving Muck diving Night diving Open-water diving Black-water diving Blue-water diving Penetration diving Ce diving Torricellian chamber Ice diving Wreck diving Recreational dive sites Underwater environment Underwater diving environment Impact Environmental impact of recreational diving Low impact diving Other Bathysphere Defense against swimmer incursions Diver detection sonar Offshore survey Rugged compact camera Underwater domain awareness Underwater vehicle Deep-submergencevehicle Aluminaut DSV Alvin American submarine NR-1 Bathyscaphe Archimède FNRS-2 FNRS-3 Harmony class bathyscaphe Sea Pole-class bathyscaphe Trieste II Deepsea Challenger Ictineu 3 JAGO Jiaolong Konsul-class submersible Limiting Factor Russian submarine Losharik Mir Nautile Pisces-class deep submergence vehicle DSV Sea Cliff DSV Shinkai DSV Shinkai 2000 DSV Shinkai 6500 DSV Turtle DSV-5 Nemo Submarine rescue International Submarine Escape and Rescue Liaison Office Submarine Escape and Rescue system (Royal Swedish Ny) McCann Rescue Chamber Submarine rescue ship Deep-submergencerescue vehicle LR5 LR7 MSM-1 Mystic-class deep-submergence rescue vehicle DSRV-1 Mystic DSRV-2 Avalon NATO Submarine Rescue System Priz-class deep-submergence rescue vehicle Russian deep submergence rescue vehicle AS-28 Russian submarine AS-34 ASRV Remora SRV-300 Submarine Rescue Diving Recompression System Type 7103 DSRV URF (Swedish Ny) Submarine escape Escape trunk Submarine escape training facility Submarine Escape Training Facility (Australia) Escape set Dis Submerged Escape Apparatus Momsen lung Steinke hood Submarine Escape Immersion Equipment Specialinterestgroups Artificial Reef Society of British Columbia CMAS Europe Coral Reef Alliance Divers Alert Network Green Fins Finger Lakes Underwater Preserve Association Karst Underwater Research Nautical Archaeology Program Nautical Archaeology Society Nal Air Command Sub Aqua Club PADI AWARE Reef Check Reef Life Survey Rubicon Foundation Se Ontario Shipwrecks SeaKeys Sea Research Society Society for Underwater Historical Research Society for Underwater Technology Underwater Archaeology Branch, Nal History & Heritage Command Neutral buoyancyfacilities forAstronaut training Neutral Buoyancy Laboratory Neutral buoyancy pool Neutral buoyancy simulation as a training aid Neutral Buoyancy Simulator Space Systems Laboratory Yuri Gagarin Cosmonaut Training Center Other Nautilus Productions Helicopter Aircrew Breathing Device Scuba diving therapy Seabed mining Category Commons Glossary Indexes: Dive sites Divers Diving Outline PortalWikimedia Commons has media related to Underwater.