Deep diving
Encyclopedia
The 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:
This definition essentially relates to recreational diving. Deep diving may have quite a different meaning in the commercial diving field. For instance the early experiments carried out by Comex S.A. (Compagnie maritime d'expertises
) using hydrox and also nitrogen trimix attained far greater depths than any recreational technical diving. One example being the Comex Janus IV open-sea dive to 500 metres, in 1977. The open-sea diving depth record was achieved in 1988 by a team of Comex divers who performed pipe line connection exercises at a depth of 534 metres in the Mediterranean Sea as part of the Hydra 8 programme. These divers needed to breathe special gas mixtures because they were exposed to very high ambient pressure (more than 50 times atmospheric pressure). An atmospheric diving suit
allows very deep dives of up to 700 metres. These suits are capable of withstanding the pressure at great depth permitting the diver to remain at normal atmospheric pressure. This eliminates the problems associated with breathing high pressure gases.
, the “narks” or “rapture of the deep”, starts with feelings of euphoria and over-confidence but then leads to numbness and memory impairment similar to alcohol intoxication. Decompression sickness
, or the “bends”, can happen if a diver ascends too fast, when excess inert gas leaves solution in the blood and tissues and forms bubbles. These bubbles produce mechanical and biochemical effects that lead to the condition. The effects tend to be delayed until reaching the surface. Bone degeneration (dysbaric osteonecrosis
) is caused by the bubbles forming inside the bones; most commonly the upper arm and the thighs. Air embolism
causes loss of consciousness
and speech and visual problems. This tends to be life threatening, and requires a recompression chamber for treatment. Deep diving involves a much greater danger of all of these, and presents the additional risk of oxygen toxicity
, which may lead to a convulsion underwater. Very deep diving using a helium–oxygen mixture (heliox
) carries a risk of high pressure nervous syndrome
. Coping with the physical and physiological stresses of deep diving requires good physical conditioning
.
Using normal scuba equipment, breathing gas
consumption is proportional to ambient pressure
- so at 50 metres (164 ft), where the pressure is 6 bar, a diver breathes 6 times as much as on the surface (1 bar). Heavy physical exertion causes even more gas to be breathed, and gas becomes denser
requiring increased effort to breathe with depth, leading to increasing risk of hypercapnia
, an excess of carbon dioxide in the blood. The need to do decompression stops increases with depth. A diver at 6 metres (19.7 ft) may be able to dive for many hours without needing to do decompression stops. At depths greater than 40 metres (131.2 ft), a diver may have only a few minutes at the deepest part of the dive before decompression stops are needed. In the event of an emergency the diver cannot make an immediate ascent to the surface without risking decompression sickness
. All of these considerations result in the amount of breathing gas required for deep diving being much greater than for shallow open water diving. The diver needs a disciplined approach to planning and conducting dives to minimise these additional risks.
Amongst technical divers
, there are certain elite divers who participate in ultra-deep diving on SCUBA (using closed circuit rebreathers
and heliox
) below 660 feet (201.2 m). Ultra-deep diving requires extraordinarily high levels of training, experience, fitness and surface support. Only eight (or possibly nine) persons are known to have ever dived below a depth of 800 feet (243.8 m) on self contained breathing apparatus recreationally.Statistics exclude military divers (classified), and commercial divers (although commercial diving to that depth is unknown on SCUBA). In 1989 the US Navy experimental diving unit published a paper entitled EX19 [a type of experimental rebreather] Performance Testing at 850 and 450 FSW which included a section on results from tests on the use of rebreather
s at 850 feet. -- That is fewer than the number of people who have walked on the surface of the moon. The Holy Grail of deep SCUBA diving was the 1000 ft (304.8 m) mark, first achieved by John Bennett in 2001, and has only been achieved five times since. Dives of this nature have been impossible to verify - proof being as tangible as faith more often than not. Since the recent introduction of depth gauge
s capable of reading to 330m it is unlikely that such records will be attempted in the future.
In 2003 Mark Ellyatt claimed dives to depths of 260m and 313m.
Besides scuba, there is a small group of divers who have reached depths below 200 meters on closed-circuit rebreathers. Some examples are David Shaw
, Don Shirley
, Alessandro Scuotto, Marco Reis, Mario Marconi, Paul Raymeakers and Pim van der Horst.
chronicles the various fatal attempts to set records as well as the smaller number of successes. From the comparatively few who survived extremely deep air dives:
In deference to the high death rate, the Guinness World Records
ceased to publish records on deep air dives.
Technical diving
Technical diving is a form of scuba diving that exceeds the scope of recreational diving...
. It is defined by the level of the diver's 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....
, diving equipment
Diving equipment
Diving equipment is equipment used by underwater divers for the purpose of facilitating diving activities. This may be equipment primarily intended for this purpose, or equipment intended for other puprposes which is found to be suitable for diving use....
, breathing gas
Breathing gas
Breathing gas is a mixture of gaseous chemical elements and compounds used for respiration.Air is the most common and only natural breathing gas...
, and surface support:
- in recreational divingRecreational divingRecreational diving or sport diving is a type of diving that uses SCUBA equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels...
, PADI define anything from 18 metres / 60 feet - 30 metres / 100 feet as a "deep dive" (other diving organisations vary) - in technical divingTechnical divingTechnical diving is a form of scuba diving that exceeds the scope of recreational diving...
, 60 metres / 200 feet may be a "deep dive" - in surface supplied divingSurface supplied divingSurface supplied diving refers to divers using equipment supplied with breathing gas using a diver's umbilical from the surface, either from the shore or from a diving support vessel sometimes indirectly via a diving bell...
, 100 metres / 330 feet may be a "deep dive"
This definition essentially relates to recreational diving. Deep diving may have quite a different meaning in the commercial diving field. For instance the early experiments carried out by Comex S.A. (Compagnie maritime d'expertises
Compagnie maritime d'expertises
COMEX is a company specializing in engineering and deep diving operations, created in November 1961 and run ever since then by Henri Germain Delauze....
) using hydrox and also nitrogen trimix attained far greater depths than any recreational technical diving. One example being the Comex Janus IV open-sea dive to 500 metres, in 1977. The open-sea diving depth record was achieved in 1988 by a team of Comex divers who performed pipe line connection exercises at a depth of 534 metres in the Mediterranean Sea as part of the Hydra 8 programme. These divers needed to breathe special gas mixtures because they were exposed to very high ambient pressure (more than 50 times atmospheric pressure). An atmospheric diving suit
Atmospheric diving suit
An atmospheric diving suit or ADS is a small one-man articulated submersible of anthropomorphic form which resembles a suit of armour, with elaborate pressure joints to allow articulation while maintaining an internal pressure of one atmosphere...
allows very deep dives of up to 700 metres. These suits are capable of withstanding the pressure at great depth permitting the diver to remain at normal atmospheric pressure. This eliminates the problems associated with breathing high pressure gases.
Particular problems associated with deep dives
Deep diving has more consequences and dangers than basic open water diving. Nitrogen narcosisNitrogen narcosis
Narcosis while diving , is a reversible alteration in consciousness that occurs while scuba diving at depth. The Greek word ναρκωσις is derived from narke, "temporary decline or loss of senses and movement, numbness", a term used by Homer and Hippocrates...
, the “narks” or “rapture of the deep”, starts with feelings of euphoria and over-confidence but then leads to numbness and memory impairment similar to alcohol intoxication. Decompression sickness
Decompression sickness
Decompression sickness describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization...
, or the “bends”, can happen if a diver ascends too fast, when excess inert gas leaves solution in the blood and tissues and forms bubbles. These bubbles produce mechanical and biochemical effects that lead to the condition. The effects tend to be delayed until reaching the surface. Bone degeneration (dysbaric osteonecrosis
Dysbaric osteonecrosis
Dysbaric osteonecrosis or DON is a form of avascular necrosis where there is death of a portion of the bone that is thought to be caused by nitrogen embolism in divers...
) is caused by the bubbles forming inside the bones; most commonly the upper arm and the thighs. Air embolism
Air embolism
An air embolism, or more generally gas embolism, is a pathological condition caused by gas bubbles in a vascular system. The most common context is a human body, in which case it refers to gas bubbles in the bloodstream...
causes loss of consciousness
Unconsciousness
Unconsciousness is the condition of being not conscious—in a mental state that involves complete or near-complete lack of responsiveness to people and other environmental stimuli. Being in a comatose state or coma is a type of unconsciousness. Fainting due to a drop in blood pressure and a...
and speech and visual problems. This tends to be life threatening, and requires a recompression chamber for treatment. Deep diving involves a much greater danger of all of these, and presents the additional risk of oxygen toxicity
Oxygen toxicity
Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen at elevated partial pressures. It is also known as oxygen toxicity syndrome, oxygen intoxication, and oxygen poisoning...
, which may lead to a convulsion underwater. Very deep diving using a helium–oxygen mixture (heliox
Heliox
Heliox is a breathing gas composed of a mixture of helium and oxygen .Heliox has been used medically since the 1930s, and although the medical community adopted it initially to alleviate symptoms of upper airway obstruction, its range of medical uses has since expanded greatly, mostly because of...
) carries a risk of high pressure nervous syndrome
High pressure nervous syndrome
High-pressure nervous syndrome is a neurological and physiological diving disorder that results when a commercial diver or scuba diver descends below about while breathing a helium–oxygen mixture. The effects depend on the rate of descent and the depth...
. Coping with the physical and physiological stresses of deep diving requires good physical conditioning
Physical fitness
Physical fitness comprises two related concepts: general fitness , and specific fitness...
.
Using normal scuba equipment, breathing gas
Breathing gas
Breathing gas is a mixture of gaseous chemical elements and compounds used for respiration.Air is the most common and only natural breathing gas...
consumption is proportional to ambient pressure
Ambient pressure
The ambient pressure on an object is the pressure of the surrounding medium, such as a gas or liquid, which comes into contact with the object....
- so at 50 metres (164 ft), where the pressure is 6 bar, a diver breathes 6 times as much as on the surface (1 bar). Heavy physical exertion causes even more gas to be breathed, and gas becomes denser
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
requiring increased effort to breathe with depth, leading to increasing risk of hypercapnia
Hypercapnia
Hypercapnia or hypercapnea , also known as hypercarbia, is a condition where there is too much carbon dioxide in the blood...
, an excess of carbon dioxide in the blood. The need to do decompression stops increases with depth. A diver at 6 metres (19.7 ft) may be able to dive for many hours without needing to do decompression stops. At depths greater than 40 metres (131.2 ft), a diver may have only a few minutes at the deepest part of the dive before decompression stops are needed. In the event of an emergency the diver cannot make an immediate ascent to the surface without risking decompression sickness
Decompression sickness
Decompression sickness describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization...
. All of these considerations result in the amount of breathing gas required for deep diving being much greater than for shallow open water diving. The diver needs a disciplined approach to planning and conducting dives to minimise these additional risks.
Dealing with depth
- Divers carry larger volumes of breathing gasBreathing gasBreathing gas is a mixture of gaseous chemical elements and compounds used for respiration.Air is the most common and only natural breathing gas...
to compensate for the increased gas consumption and decompression stops. - RebreatherRebreatherA 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 manage gas much more efficiently than open circuit scuba, but are inherently more complex than open circuit scuba. - Use of helium-based breathing gases such as trimix reduces nitrogen narcosis and stays below the limits of oxygen toxicity.
- A diving shotDiving shotthumb|right|Diagram of a diving shot upcurrent of a dive siteA diving shot is an item of diving equipment consisting of a weight, a line and a buoy. The weight is dropped on the dive site. The line connects the weight and the buoy and is used by divers to move between the surface and the dive site...
, a decompression trapeze or a decompression buoy can help divers return to their surface safety cover at the end of a dive.
Ultra-deep diving
| Name | Location | Depth | Year |
|---|---|---|---|
| Nuno Gomes Nuno Gomes (diver) Nuno Gomes is a South African SCUBA diver who holds the official current world record deep dive . He used self contained underwater breathing apparatus to dive to a depth of 1,044 feet... |
Red Sea Red Sea South Africa South Africa |
1044 feet (318.2 m) 890 feet (271.3 m) 927 feet (282.5 m) 826 feet (251.8 m) |
2005 2004 1996 1994 |
| Pascal Bernabé Pascal Bernabé Pascal Bernabé is a French SCUBA diver who lays claim to the world best for depth on a deep dive using self-contained breathing apparatus. Bernabé used trimix to dive to 330 meters 5 June 2005 near Propriano, Corsica. This is actually deeper than the official deepest scuba dive recognized by... |
Mediterranean Mediterranean |
1083 feet (330.1 m) 873 feet (266.1 m) |
2005 2005 |
| David Shaw David Shaw (diver) David Shaw was an Australian scuba diver, a technical diver and an airline pilot for Cathay Pacific, who flew the A330-300, A340-300 and A340-600... |
South Africa | 888 feet (270.7 m) | 2004 |
| Gilberto M de Oliveira | Brazil | 898 feet (273.7 m) | 2002 |
| John Bennett John Bennett (diver) John Bennett was a British SCUBA diver who is best known for setting a world record by becoming the first person to deep dive below a depth of 1,000 feet on self contained breathing apparatus on 6 November 2001.... |
Philippines Philippines |
1010 feet (307.8 m) 833 feet (253.9 m) |
2001 2001 |
| Jim Bowden Jim Bowden (diver) Jim Bowden is an American SCUBA diver, and an elite technical diver, famous as a cave diver and as a deep diver. In 1994 he set a world record, since broken, by diving to . He is one of only eight people who have dived below a depth of on self contained breathing apparatus... |
Mexico Mexico |
925 feet (281.9 m) 825 feet (251.5 m) |
1994 1993 |
| Sheck Exley Sheck Exley -Biography:Exley is widely regarded as one of the pioneers of cave diving, writing two major books on the subject: Basic Cave Diving: A Blueprint for Survival and Caverns Measureless to Man published by Cave Books, , and establishing many of the basic safety procedures used in cave and overhead... |
South Africa Mexico |
863 feet (263 m) 867 feet (264.3 m) |
1993 1989 |
| Don Shirley Don Shirley (diver) Don Shirley is a world renowned English cave diver and Instructor Trainer and who currently resides in South Africa. He holds the license to International Association of Nitrox and Technical Divers Southern Africa Region. Shirley has been involved in diving since 1974, conducting recreational... |
South Africa | 820 feet (249.9 m) | 2005 |
| Mark Ellyatt | Andaman Sea Thailand |
1026 feet (312.7 m) 850 feet (259.1 m) |
2003 2003 |
Amongst technical divers
Technical diving
Technical diving is a form of scuba diving that exceeds the scope of recreational diving...
, there are certain elite divers who participate in ultra-deep diving on SCUBA (using closed circuit rebreathers
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...
and heliox
Heliox
Heliox is a breathing gas composed of a mixture of helium and oxygen .Heliox has been used medically since the 1930s, and although the medical community adopted it initially to alleviate symptoms of upper airway obstruction, its range of medical uses has since expanded greatly, mostly because of...
) below 660 feet (201.2 m). Ultra-deep diving requires extraordinarily high levels of training, experience, fitness and surface support. Only eight (or possibly nine) persons are known to have ever dived below a depth of 800 feet (243.8 m) on self contained breathing apparatus recreationally.Statistics exclude military divers (classified), and commercial divers (although commercial diving to that depth is unknown on SCUBA). In 1989 the US Navy experimental diving unit published a paper entitled EX19 [a type of experimental rebreather] Performance Testing at 850 and 450 FSW which included a section on results from tests on the 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 at 850 feet. -- That is fewer than the number of people who have walked on the surface of the moon. The Holy Grail of deep SCUBA diving was the 1000 ft (304.8 m) mark, first achieved by John Bennett in 2001, and has only been achieved five times since. Dives of this nature have been impossible to verify - proof being as tangible as faith more often than not. Since the recent introduction of depth gauge
Depth gauge
A 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...
s capable of reading to 330m it is unlikely that such records will be attempted in the future.
In 2003 Mark Ellyatt claimed dives to depths of 260m and 313m.
Besides scuba, there is a small group of divers who have reached depths below 200 meters on closed-circuit rebreathers. Some examples are David Shaw
David Shaw (diver)
David Shaw was an Australian scuba diver, a technical diver and an airline pilot for Cathay Pacific, who flew the A330-300, A340-300 and A340-600...
, Don Shirley
Don Shirley (diver)
Don Shirley is a world renowned English cave diver and Instructor Trainer and who currently resides in South Africa. He holds the license to International Association of Nitrox and Technical Divers Southern Africa Region. Shirley has been involved in diving since 1974, conducting recreational...
, Alessandro Scuotto, Marco Reis, Mario Marconi, Paul Raymeakers and Pim van der Horst.
Ultra deep air
While extreme deep diving on air is extremely dangerous, before the popularity of Trimix attempts were made to set world record depths using conventional air. This created an extreme risk of both narcosis and oxygen toxicity in the divers and, perhaps unsurprisingly, contributed to an astonishingly high fatality rate amongst those attempting records. In his book, Deep Diving, Bret GilliamBret Gilliam
Bret Clifton Gilliam is a pioneering technical diver. He is most famous as the founder of TDI, and as the one time holder of the world record for deep diving on air....
chronicles the various fatal attempts to set records as well as the smaller number of successes. From the comparatively few who survived extremely deep air dives:
- 1947 Frédéric DumasFrédéric DumasFrédéric Dumas was part of a team of three, with Jacques-Yves Cousteau and Philippe Tailliez, in which he was nicknamed Didi. They had a passion for diving, and developed the diving regulator with the aid of the engineer Émile Gagnan...
, a colleague of Jacques Cousteau, dived to 307 feet (93.6 m) on air - 1959 Ennio Falco reported having reached a depth of 435 feet (132.6 m) on air, but had no means to record it
- 1965 Tom MountTom MountTom Mount is a pioneering technical diver. In 1991 Tom Mount joined Dick Rutkowski in the new organisation formed by Rutkowski, IANTD, dedicated to teaching Nitrox to recreational divers. In 1992 Tom was named President and Chief Executive Office of IANTD, a position that he held until 2005...
and Frank Martz dive to a depth of 360 feet (109.7 m) on air - 1967 Hal Watts and AJ Muns dive to a depth of 390 feet (118.9 m) on air
- 1968 Neil Watson and John Gruener dived to 437 feet (133.2 m) on air in the Bahamas. Watson reported that he had no recollection at all of what transpired at the bottom of the descent due to narcosis.
- 1990 Bret GilliamBret GilliamBret Clifton Gilliam is a pioneering technical diver. He is most famous as the founder of TDI, and as the one time holder of the world record for deep diving on air....
dived to a depth of 452 feet (137.8 m) on air. Unusually, Gilliam remained largely functional at depth and was able to complete basic maths problems and answer simple questions written on a slate by his crew beforehand. - 1993 Bret Gilliam extended his own world record to 475 feet (144.8 m), again reporting no ill effects from narcosis or oxygen toxicity.
- 1994 Dan Manion set the current record for a deep dive on air at 509 feet (155.1 m). Manion reported he was almost completely incapacitated by narcosis and has no recollection of time at depth.
In deference to the high death rate, the Guinness World Records
Guinness World Records
Guinness World Records, known until 2000 as The Guinness Book of Records , is a reference book published annually, containing a collection of world records, both human achievements and the extremes of the natural world...
ceased to publish records on deep air dives.
See also
- Decompression sicknessDecompression sicknessDecompression sickness describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization...
- Breathing gasBreathing gasBreathing gas is a mixture of gaseous chemical elements and compounds used for respiration.Air is the most common and only natural breathing gas...
- 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...
, diving without breathing - HelioxHelioxHeliox is a breathing gas composed of a mixture of helium and oxygen .Heliox has been used medically since the 1930s, and although the medical community adopted it initially to alleviate symptoms of upper airway obstruction, its range of medical uses has since expanded greatly, mostly because of...
- HydrelioxHydrelioxHydreliox is an exotic breathing gas mixture of helium, oxygen and hydrogen.It is used primarily for research and scientific deep diving, usually below . Below this depth, extended breathing of heliox gas mixtures may cause high pressure nervous syndrome . Two gas mixtures exist that attempt to...
- High pressure nervous syndromeHigh pressure nervous syndromeHigh-pressure nervous syndrome is a neurological and physiological diving disorder that results when a commercial diver or scuba diver descends below about while breathing a helium–oxygen mixture. The effects depend on the rate of descent and the depth...
- Oxygen toxicityOxygen toxicityOxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen at elevated partial pressures. It is also known as oxygen toxicity syndrome, oxygen intoxication, and oxygen poisoning...
- Trimix