Deep diving

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Deep within is diving underwater to a depth beyond the norms received by the community concerned. In some cases, this is a prescribed limit set by the authority, and on the other hand it is related to the level of certification or training, and it may vary depending on whether the dive is recreational, technical or commercial. Narcotic nitrogen becomes a hazard below 30 meters (98 feet) and hypoxic respiratory gas is required under 60 meters (200 feet) to reduce the risk of oxygen toxicity. Professional divers can use the atmospheric diving setting that allows deep dives of up to 610 meters (2,000 feet).

For some recreational diving agencies, Diving in , or Diver in is probably a certification given to diver who has been trained to dive to a certain depth range, generally deeper than 30 meters ( 98Ã, ft). However, the Association of Professional Diving Instructors (PADI) defines anything from 18 meters (60à fÂ, ft) to 30 meters (100Ã, ft) as "deep dive" in the context of diving recreation (other dive organizations vary), and consider deep diving a form of technical dive.

In technical diving, a depth below about 60 meters (200 feet) where hypoxic respiratory gas becomes necessary to avoid oxygen toxicity can be considered as a "deep dive".

In professional diving, depth requiring special equipment, procedures, or advanced training can be considered as a deep dive.

Diving in can mean something else in the field of commercial dives. For example the initial experiments performed by Comex S.A. (Compagnie maritime d'expertises) using hydroks and trimix reaches far greater depth than the technical leisure dive. One example is the Comex Janus IV open-sea dive of up to 501 meters (1,644 feet) in 1977. Note the depth of the open sea was achieved in 1988 by the Comex divers team conducting pipeline training at a depth of 534 meters. (1,752Ã, ft) in the Mediterranean Sea as part of the Hydra 8 program. The diver is required to inhale special gas mixtures because they are exposed to very high ambient pressure (more than 50 times atmospheric pressure).

The atmospheric diving setting allows deep dives of up to 2,000 feet (610 m). This outfit is able to withstand pressure at depth which allows the diver to remain at normal atmospheric pressure. This eliminates the problems associated with high-pressure gas respiration.

Video Deep diving

The depth range in underwater diving

Maps Deep diving

Special issues related to deep dives

Deep diving has more dangers and greater risks than basic open water dives. Narcotics Nitrogen, "narks" or "rapture of the deep", starts with a feeling of euphoria and overconfidence but then leads to numbness and memory impairment similar to alcohol poisoning. Decompression disease, or "bend", can occur if a diver rises too quickly, when the excess gas solution is inert in the blood and tissues and forms a bubble. These bubbles produce mechanical and biochemical effects that lead to the condition. The onset of symptoms depends on the severity of the loading of the tissue gases and can develop during ascent in severe cases, but is often delayed until it reaches the surface. Bone degeneration (dysbaric osteonecrosis) is caused by bubbles formed in bone; most often the upper arm and thigh. Deep diving involves a far greater danger than all of these, and presents an additional risk of oxygen toxicity, which can cause seizures under water. A very deep dive using a mixture of helium-oxygen (heliox) carries the risk of high-pressure nerve syndrome. Overcoming physical and physiological pressure dives in need of good physical condition.

Using normal scuba equipment, the consumption of respiratory gas is proportional to ambient pressure - so at 50 meters (160 feet), where the pressure is 6 bar, a diver breathes 6 times more than the surface (1 bar). The heavy exertion makes the diver inhale more gas, and the gas becomes denser which requires increased effort to breathe with depth, leading to an increased risk of hypercapnia - the excess carbon dioxide in the blood. The need for decompression stops increasing with depth. A diver at 6 meters (20 feet) can dive for hours without having to decompress a halt. At a depth of more than 40 meters (130 feet), the diver may only have a few minutes at the deepest part of the dive before the required decompression stops. In an emergency, the diver can not directly rise to the surface without risk of decompression disease. All of these considerations result in the amount of breathing gas needed for diving far greater than for shallow open water dives. Divers need a disciplined approach to plan and dive to minimize these additional risks.

Many of these problems are avoided by the use of surface-supplied breathing gas, closed diving bells, and saturation dives, at the expense of logistical complexity, reducing the ability of divers maneuvers and greater costs.

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Dealing with depth

Both equipment and procedures can be tailored to deal with deeper issues. Usually both are combined, because the procedure must be adjusted to fit the equipment, and in some cases equipment is required to facilitate the procedure.

Adaptation of deep diving equipment

The equipment used for deep diving depends on the depth and type of diving. Scuba is limited to equipment that can be carried by divers, or easily deployed by divers teams, while submarine equipment provided on the surface can be wider, and many of them are on the water where it is operated by a support team.

• Scuba divers brings greater volume of breathing gas to offset increased gas consumption and decompression cessation.
• Rebreathers manage gases much more efficiently than open-circuit scuba, but are inherently more complex than open-circuit scuba.
• The use of helium-based breathing gas such as trimix reduces nitrogen narcosis and remains below the oxygen toxicity limit.
• Diving injections, decompression trapeze or decompression buoys can help divers control their ascent and return to the surface in a position that their surface support team can monitor at the end of the dive.
• Decompression can be accelerated by using a special mixed gas mixture containing a lower proportion of inert gas.
• Respiratory gas supply reduces the risk of running out of gas.
• Decompression in water can be minimized by using dry bells and decompression chambers.
• Hot water settings can prevent hypothermia from high heat loss when using helium respiratory gas.
• Diving bells and submersible locking expose the diver to the immediate subsea environment for a shorter time, and provide a relatively safe shelter that does not require decompression, with a dry environment where divers can take a break, take refreshments and, if necessary, receive first aid in an emergency.
• The respiratory gas reclamation system reduces the cost of using helium-based breathing gas, by recovering and recycling gas supplied from the air surface, analogous to rebreathers for scuba diving.
• The most radical adaptation of the deep diving equipment is to isolate the diver from direct environmental stress, using the armor-plated atmospheric clothing that allows diving into the outside depth which may be currently at ambient pressure. This rigid and articulated exoskeleton dress is sealed against water and withstand external pressure while providing live support for divers for several hours at an internal pressure around normal surface atmospheric pressure. It avoids the problem of inert gas narcotics, decompression diseases, barotrauma, oxygen toxicity, high respiratory work, arthralgia compression, high-pressure nervous syndrome and hypothermia, but at the expense of reduced mobility and agility, logistical problems due to bulk and masses of clothing, and high equipment costs.

Procedural adaptations for deeper dive

Procedural adaptations for deep diving can be classified as procedures for operating specific equipment, and that are applied directly to problems caused by high exposure to ambient pressure.

• The most important procedure for dealing with respiratory physiological problems at high ambient pressure associated with deep diving is decompression. This is necessary to prevent the formation of inert gas bubbles in the body tissue of divers, which can cause severe injury. The decompression procedure has been derived for a large amount of exposure pressure, using a large amount of gas mixture. This essentially requires slow and controlled pressure reduction during the climb by using a limited climbing rate and decompression stops, so that the inert gas dissolved in the diver tissue can be removed without danger during normal respiration.
• Gas management procedures are required to ensure that divers have access to respiratory gas appropriate and adequate at all times during dives, for both planned dive profiles and for any presumed possibility. Scuba gas management is logistically more complex than surface supply, because divers have to carry all the gas, must follow the route where the pre-arranged gas supply depot is set (stage cylinder). or have to rely on a support diver team that will provide additional gas on pre-arranged signals or points on planned dives. On very deep dives or on occasions where long decompression times are planned, it is common practice for divers support to meet the main team on the decompression deck to check if they need help, and these support divers will often bring in extra gas supplies if needs. The use of rebreathers can reduce most of the gas supply for long and deep scuba diving, with the cost of more complex equipment with more potential failure modes, requiring more complex procedures and the loading of more procedural tasks.
• The dives supplied on the surface distribute the tasks between the diver and the support team, which remain in the relative safety and comfort of the surface control position. The gas supply is limited only by what is available in the control position, and the diver only needs to bring enough bailout capacity to reach the nearest safe place, which may be diving or locking submarine.
Saturation diving is a procedure used to reduce the high risk decompression experienced by divers during a long series of deep underwater exposures. By keeping the diver under high pressure for all the work, and just decompressing at the end of a few days to an underwater working week, a single decompression can be done at a slower rate without adding much overall time to the job. During the saturation period, divers live in pressurized environments on the surface, and are transported under pressure to the workplace underwater in closed dive bells.

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Diving deep

Among the technical divers, there are divers who participate in ultra-deep dives in SCUBA below 200 meters (660 ft). This practice requires high levels of training, experience, discipline, fitness, and surface support. Only twelve people are known to have dived under a depth of 240 meters (790 feet) on a self-sustaining recreational respirator. That is an amount equal to the number of people walking on the moon. The Holy Grail of deep scuba diving is a 300 m (980 ft) mark, first achieved by John Bennett in 2001, and has only been achieved five times since.

Difficulties in relation to ultra-deep diving are numerous. Although commercial and military divers often operate at such depths, or even deeper, they are supplied to the surface. All the complexities of ultra-deep diving are magnified by the need for divers to bring (or supply) their own underwater gas. This leads to quick descents and "bounce dives". Not surprisingly, this has led to a very high mortality rate among those who practice ultra deep diving. The deepest diving crimes include Sheck Exley, John Bennett, Dave Shaw, and Guy Garman. Mark Ellyatt, Don Shirley and Pascal Bernabà © were involved in serious incidents and were fortunate to survive their dives. Despite a very high mortality rate, the Guinness Book of World Records continues to maintain records for scuba diving (though to honor the death rate it has stopped recording records for deep dives in the air). Among those who survived significant health problems were reported. Mark Ellyatt is reported to be suffering from permanent lung damage; Pascal Bernabà ©  © (who was injured while diving when the light on his mask exploded) and Nuno Gomes reported short to medium term hearing loss.

The serious problems faced by divers who are involved in ultra-deep diving in self-contained breathing apparatus include:

• High-pressure syndrome (HPNS). HPNS, which occurs by inhaling helium under extreme pressure causes tremor, myoclonic jerking, somnolence, EEG changes, visual disturbances, nausea, dizziness, and decreased mental performance. The symptoms of HPNS are compounded by rapid compression, a common feature for ultra-deep "bounce" dives.
• Decompression algorithm. No reliable decompression algorithm is tested for such depth on direct surface assumptions. Almost all decompression methodologies for the depth are based on saturation, and calculate the climb time in a few days rather than hours. Therefore, ultra-deep diving is almost always a partial experimental base.

In addition, "usual" risks such as gas reserves, hypothermia, dehydration, and oxygen toxicity are exacerbated by extreme depth and exposure. Many technical equipment are not designed for greater pressure at depth, and major equipment reports (including pressure gauges that can be recycled) are not uncommon.

Verna van Schaik in 2004 set the Guinness Women's World Record for the deepest diving by diving to 221 meters (725 ft) in the Boesmansgat cave.

Claudia Serpieri in 2000 reached 211 meters (692 feet), the deepest sea diving by a woman.

Tatiana Oparina in 2015, reaches 156 m in Lake Baikal, the deepest dive in extreme cold water (3C) by a woman.

The air is deepest

While extreme dive in the air is very dangerous, before the popularity of Trimix's efforts was made to set the depth of the world record using conventional air. This creates the extreme risk of narcotics and oxygen toxicity to divers and contributes to the high mortality rate among those trying to record. In his book, Deep Diving, Bret Gilliam recounts fatal attempts to make notes and fewer success figures. Of the relatively few survivors of deep air dives:

• 1947 FrÃÆ' Â © dico Dumas, a colleague of Jacques Cousteau, diving 94 meters (308 feet) in the air
• 1947 Maurice Fargues, another Jacques Cousteau colleague, dived up to 117 meters (384 feet) in the air but died after a loss of consciousness at depth
• 1957 Eduard Admetlla i LÃÆ'¡zaro drops to 100 meters in air
• 1959 Ennio Falco reported to have reached a depth of 133 meters (436 feet) in the air, but lacked the means to record it
• 1965 Tom Mount and Frank Martz dive to a depth of 110 meters (360Ã, ft) in the air
• 1967 Hal Watts and AJ Muns dive to a depth of 120 meters (390Ã, ft) in the air
• 1968 Neil Watson and John Gruener dive up to 133 meters (436 feet) in the air in the Bahamas. Watson reported that he did not have any memory at all about what happened at the bottom of the descent because of narcosis.
• 1971 Sheck Exley dives to 142 meters (466Ã, ft) in the air on December 11 near Andros Island in the Bahamas. Exley should only descend to 91 meters (299 feet) in his capacity as a safety diver (although he has practiced several dives up to 120 meters (390 feet) in preparation), but descended to find a submarine after they failed. to get back on schedule. Exley almost made it to the diver, but was forced to return because of heavy anesthesia and almost fainted.
• 1990 Bret Gilliam dived to a depth of 138 meters (453 feet) in the air. Unusually, Gilliam remained largely in depth and was able to solve basic math problems and answer simple questions written on slate by his previous crew.
• 1993 Bret Gilliam extended her own world record to 145 meters (476 feet), again reporting no ill effects from narcosis or oxygen toxicity.
• 1994 Dan Manion set the current record for diving deep in the air at 155 meters (509 feet). Manion reports he is almost completely paralyzed by narcosis and has no memory of time at depth.

In honor of the high mortality rate, Guinness World Records stopped publishing records of deep air diving in mid 2005.

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Fatalities during deep record effort

• Maurice Fargues died in 1947 in an experiment to see how deep a scuba diver could go.
• Hope Root died in December 1953 trying to break the record of deep diving from 330 feet; he was last seen through 625 feet.
Archie Forfar and Anne Gunderson died on December 11, 1971 off the coast of Andros Island, Bahamas while trying to dive to 480 feet, which would be a world record at the time. Their third team member, Jim Lockwood, only survived because of the heavy use of safety that went down when he lost consciousness - causing him to start an uncontrollable ascent before being intercepted by safety divers about 300 feet deep. As mentioned above, Sheck Exley, who acted as another safety diver at 300 feet, accidentally managed to record depth records as he descended to Forfar and Gunderson, both of whom were still living at 480 feet, albeit completely paralyzed by narcosis. Exley was forced to let go of his efforts at about 465 feet when narcosis very nearly defeated him as well. The bodies of Forfar and Gunderson were never found.
• Sheck Exley died in 1994 in an effort to reach the bottom of ZacatÃÆ'³n in a dive that would extend his own world record (at the time) to dive in.
• Dave Shaw died in 2005 in the deepest and deepest recovery effort of the body ever dive in rebreather.
• Guy Garman died on August 15, 2015 in a failed attempt to dive up to 1,200 feet (370 m). The Virgin Islands Police Department confirmed that the body of Dr Guy Garman was discovered on Tuesday, August 18, 2015.

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See also

• Decompression disease
• Respiratory Gas
• Diving is free, diving without breathing
• Heliox
• Hydreliox
• High-pressure syndrome
• Oxygen toxicity
• Trimix

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References

Footnote

src: www.scubadiving.com

Further reading

• Dent, W (2006). "AAUS Deep Diving Standards". In: Lang, MA and Smith, NE (eds). Proceeding of Advanced Scientific Diving Workshop . Smithsonian Institution, Washington, DC . Retrieved 2008-07-05 .
• Gilliam, Bret (1995). Deep Diving: Advanced Guide to Physiology, Procedures & amp; System (issue 2). Watersports Books. ISBN: 0-922769-31-1.

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External links

• Deep Diving Recreation

Source of the article : Wikipedia