Deep diving

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Deep diving

The meaning of the term deep diving is a form of technical diving

Technical diving

Technical diving is a form of scuba diving that exceeds the scope of recreational diving . Technical divers require advanced training, extensive experience, specialized equipment and often breathe breathing gases other than air or standard nitrox....
. 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 diving activities safely and have fun....
, diving equipment

Diving equipment

The fundamental item of diving equipment used by divers is the Scuba sets, such as the Aqua-Lung or Rebreather. There are other important pieces of equipment that make diving safer, more convenient or more efficient....
, breathing gas

Breathing gas

Air is the most common and only natural breathing gas. Other artificial gases, either pure gases or mixtures of gases, are used in breathing equipment and enclosed habitats such as Scuba set, surface supplied diving equipment, recompression chambers, submarines, space suits, spacecraft and anaesthetic machines....
, and surface support:

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Deep Diving

DepthAll depths specified for sea water. Fractionally deeper depths may apply in relation to freshwater due to its lower density

Comments

40 feet/12 meters

Recreational diving limit for divers aged under 12 years old and beginner divers.

60 feet/18 meters

Recreational diving limit for divers with Open Water certification but without greater training and experience.

100 feet/30 meters

Recommended recreational diving limit for divers.

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Encyclopedia

The meaning of the term deep diving is a form of technical diving

Technical diving

Diver training

Diving equipment

Breathing gas

in recreational diving
Recreational diving

Recreational diving or sport diving is a type of Underwater diving that uses Scuba set 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 of training, experience and equip...
, 30 metres / 100 feet may be a "deep dive"
in technical diving
Technical diving

Technical diving is a form of scuba diving that exceeds the scope of recreational diving . Technical divers require advanced training, extensive experience, specialized equipment and often breathe breathing gases other than air or standard nitrox....
, 60 metres / 200 feet may be a "deep dive"
in surface supplied diving
Surface supplied diving

Surface supplied diving refers to diving activities using equipment supplied with breathing gas using an Umbilical cord#Other uses for the term "umbilical cord" from the surface, often from a diving support vessel but possibly, indirectly via a diving chamber....
, 100 metres / 330 feet may be a "deep dive"

**Deep Diving**
DepthAll depths specified for sea water. Fractionally deeper depths may apply in relation to freshwater due to its lower density	Comments
40 feet/12 meters	Recreational diving limit for divers aged under 12 years old and beginner divers.
60 feet/18 meters	Recreational diving limit for divers with Open Water certification but without greater training and experience.
100 feet/30 meters	Recommended recreational diving limit for divers. Average depth at which nitrogen narcosis Nitrogen narcosis Narcosis while diving, commonly called nitrogen narcosis, inert gas narcosis or rapture of the deep, is a reversible alteration in consciousness in Scuba diving at depth.... symptoms begin to appear in adults.
130 feet/40 meters	Absolute recreational diving limit for divers specified by Recreational Scuba Training Council (RSTC).
180 feet/55 meters	Technical diving limit for "extended range" dives breathing air to a maximum pp Partial pressure In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. The total pressure of a gas mixture is the sum of the partial pressures of each individual gas in the mixture.... O₂ Oxygen Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]... of 1.4 ATA Atmosphere (unit) The standard atmosphere is an international reference pressure defined as 101,325 Pascal and formerly used as unit of pressure . For practical purposes it has been replaced by the Bar which is 100,000 Pa.... .
218 feet/65 meters	Depth at which compressed air results in an unacceptable 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, hyperoxia, or the Paul Bert effect and Lorrain Smith effect, after the researchers who pioneered its discovery and desc... Oxygen toxicity depends upon a combination of partial pressure and time of exposure, individual physiology, and other factors not fully understood. NOAA National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the Earth's atmosphere.... recommends that divers do not expose themselves to breathing oxygen at greater than 1.6 bar pp Partial pressure In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. The total pressure of a gas mixture is the sum of the partial pressures of each individual gas in the mixture.... O₂ Oxygen Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]... , which occurs at 218 feet breathing air.
330 feet/100 meters	Technical diving training limit for divers breathing trimix. Recommended technical diving limit.
660 feet/200 meters	Absolute limit for surface light penetrationAssuming crystal clear water; surface light may disappear completely at much shallower depths in murky conditions.
1,083 feet/330 meters	World record for deepest dive on SCUBA 1,083 feet was the depth reportedly achieved by Pascal Bernabé Pascal Bernabé Pascal Bernab? is a France Scuba diving who lays claim to the world record for depth on a deep diving on self-contained breathing apparatus, at 330 meters , in 2005.... in 2005. However, 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 an internationally recognized... still recognises the 1,044 feet dive by Nuno Gomes (diver) Nuno Gomes (diver) Nuno Gomes is a South African Scuba diving who holds the official current world record deep diving using self contained breathing apparatus , having dived to a depth of 1,044 feet excluding the rope stretch, in the Red Sea off the coast of Egypt, in 2005.... earlier in the same year as the current official world record.

Particular problems associated with deep dives

Deep diving obviously has more consequences and dangers than basic open water diving. Nitrogen narcosis

Nitrogen narcosis

Narcosis while diving, commonly called nitrogen narcosis, inert gas narcosis or rapture of the deep, is a reversible alteration in consciousness in Scuba diving at depth....
, or the “narks” or “rapture of the deep”, starts with feelings of euphoria and over-confidence but then lead to numbness and memory impairment similar to alcohol intoxication. Decompression sickness

Decompression sickness

'Decompression sickness' , 'the diver?s disease', 'the bends', 'caisson disease' is the name given to a variety of symptoms suffered by a person exposed to a decrease in the pressure around the body....
, or the “bends”, is when the gas bubbles of nitrogen get caught in the joints on an ascent. Yet, 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 the death of a portion of the bone that is thought to be caused by nitrogen embolization 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 medical condition caused by gas bubbles in the bloodstream . Small amounts of air often get into the blood circulation accidentally during surgery and other medical procedures , but most of these air emboli enter the veins and are stopped at the lungs, and thus a venous air embolism...
causes loss of consciousness

Unconsciousness

Unconsciousness, more appropriately referred to as loss of consciousness or lack of consciousness, is a dramatic alteration of mental state that involves complete or near-complete lack of responsiveness to people and other environmental stimuli....
and speech and visual problems. This tends to be life threatening, but sometimes the symptoms resolve before the recompression chamber

Recompression chamber

A recompression chamber is a pressure vessel used to treat divers suffering from certain diving disorders such as decompression sickness.Often the terms recompression chamber, decompression chamber, hyperbaric chamber, and hyperbaric oxygen therapy chamber are used interchangeably....
are needed. All these are harms and possibly worse effects of deep diving. These physical and physiological stresses require good physical conditioning

Physical fitness

Physical fitness is used in two close meanings: general fitness and specific fitness .Physical fitness is the functioning of the heart, blood vessels, lungs, and muscles at optimum efficiency....
.

High breathing gas
Breathing gas

Air is the most common and only natural breathing gas. Other artificial gases, either pure gases or mixtures of gases, are used in breathing equipment and enclosed habitats such as Scuba set, surface supplied diving equipment, recompression chambers, submarines, space suits, spacecraft and anaesthetic machines....
consumption. Gas consumption is proportional to pressure - so at 50 metres / 165 feet (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.
Increased nitrogen narcosis
Nitrogen narcosis

Narcosis while diving, commonly called nitrogen narcosis, inert gas narcosis or rapture of the deep, is a reversible alteration in consciousness in Scuba diving at depth....
. This causes stress and inefficient thinking in the diver. When breathing air
Breathing gas

Air is the most common and only natural breathing gas. Other artificial gases, either pure gases or mixtures of gases, are used in breathing equipment and enclosed habitats such as Scuba set, surface supplied diving equipment, recompression chambers, submarines, space suits, spacecraft and anaesthetic machines....
many divers find 40 metres / 130 feet a safe maximum depth.
The need to do decompression stop
Decompression stop

A decompression stop is a period of time a SCUBA diving must spend at a constant depth in shallow water at the end of a dive to safely eliminate absorbed inert gases from the diver's body to avoid decompression sickness....
s increases with depth. A diver at 6 metres may be able to dive for many hours without needing to do decompression stops. At depths greater than 40 metres / 130 feet, 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' , 'the diver?s disease', 'the bends', 'caisson disease' is the name given to a variety of symptoms suffered by a person exposed to a decrease in the pressure around the body....
. The diver needs a disciplined approach to planning and conducting dives and needs to carry extra gas for the decompression stops to reduce the risk of being unable to complete the stops.
Drifting. If long decompression stops are carried out in a tidal current, the divers may drift away from their boat
Boat

A boat is a watercraft of modest size designed to float or plane on water, and provide transport over it. Usually this water will be inland or in protected coastal areas....
cover or a safe exit point on the shore.
Increased breathing effort. Gas becomes denser
Density

The density of a material is defined as its mass per unit volume. The symbol of density is ....
and the effort required to breathe increases with depth (work of breathing).
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. Carbon dioxide is a gaseous product of the human body metabolism and is normally expelled through the lungs....
, an excess of carbon dioxide in the blood.
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, hyperoxia, or the Paul Bert effect and Lorrain Smith effect, after the researchers who pioneered its discovery and desc...
.
High pressure nervous syndrome
High pressure nervous syndrome

High pressure nervous syndrome is a neurological and physiological diving disorders that results when a SCUBA diving spends too much time breathing a high-pressure mixture of helium and oxygen ....
.

Dealing with depth

Carry larger volumes of breathing gas
Breathing gas

Air is the most common and only natural breathing gas. Other artificial gases, either pure gases or mixtures of gases, are used in breathing equipment and enclosed habitats such as Scuba set, surface supplied diving equipment, recompression chambers, submarines, space suits, spacecraft and anaesthetic machines....
to compensate for the increased gas consumption and decompression stops.
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 humans cannot safely breathe from the atmosphere....
s are much more efficient consumers of gas than open circuit scuba and inherently more complex than open circuit scuba.
Use helium-based breathing gases such as trimix
Trimix

Trimix is a breathing gas, consisting of oxygen, helium and nitrogen, and is often used in deep commercial diving and during the deep phase of dives carried out using technical diving techniques....
to reduce nitrogen narcosis and stay beyond the limits of oxygen toxicity.
A diving shot
Diving shot

A diving shot is an item of diving equipment consisting of a weight, a line and a buoy....
, a decompression trapeze
Decompression trapeze

A decompression trapeze is a device used in recreational diving and technical diving to make decompression stops more comfortable and more secure and provide the divers' surface cover with a visual reference for the divers' position....
or a decompression buoy can help divers return to their surface safety cover at the end of a dive.

Ultra-deep diving

Amongst technical divers

Technical diving

Technical diving is a form of scuba diving that exceeds the scope of recreational diving . Technical divers require advanced training, extensive experience, specialized equipment and often breathe breathing gases other than air or standard nitrox....
, 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 humans cannot safely breathe from the atmosphere....
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 the low density of the gas....
) below 660 feet/200 metres. 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 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

List of Apollo astronauts

This is a list of all astronauts directly associated with NASA's Project Apollo. A total of thirty-eight astronauts flew in an Apollo spacecraft, twenty-nine of whom were part of the Apollo program, the rest being Skylab and Apollo-Soyuz astronauts....
. The Holy Grail of deep diving was the 1000 ft. mark, first achieved by John Bennett in 2001, and has only been achieved twice since.

**Verified dives below 800 feet**
Name	Location	Depth	Year
Nuno Gomes Nuno Gomes (diver) Nuno Gomes is a South African Scuba diving who holds the official current world record deep diving using self contained breathing apparatus , having dived to a depth of 1,044 feet excluding the rope stretch, in the Red Sea off the coast of Egypt, in 2005....	Red Sea Red Sea South Africa South Africa	1,044 feet 890 feet 927 feet 826 feet	2005 2004 1996 1994
Pascal Bernabé Pascal Bernabé Pascal Bernab? is a France Scuba diving who lays claim to the world record for depth on a deep diving on self-contained breathing apparatus, at 330 meters , in 2005....	Mediterranean Mediterranean	1,083 feet 873 feet	2005 2005
David Shaw David Shaw (diver) David Shaw was an Australian Scuba diving, and an elite technical diving. He is one of Deep diving#Ultra-deep diving who have dived below a depth of 240 meters / 800 feet on Underwater_diving#Diving_with_Self_Contained_Underwater_Breathing_Apparatus_.28SCUBA.29....	South Africa	888 feet	2004
G.M de Oliveira	Brazil	898 feet	2002
John Bennett John Bennett (diver) John Bennett was a United Kingdom Scuba diving who is best known for setting a world record by becoming the first person to deep diving below a depth of 1,000 feet on self contained breathing apparatus....	Philippines Philippines	1,010 feet 833 feet	2001 2001
Ricks Pool Philippines	2,00 feet 833 feet	2001 2001
Jim Bowden Jim Bowden (diver) Jim Bowden is an United States Scuba diving, and an elite technical diving, famous as a cave diving and as a deep diving. In 1994 he set a world record, since broken, by diving to 925 feet....	Mexico Mexico	925 feet 825 feet	1994 1993
Sheck Exley Sheck Exley Sheck Exley was a cave-diving pioneer....	South Africa Mexico	863 feet 867 feet	1993 1989
Don Shirley Don Shirley (diver) Don Shirley is a world renowned English Cave diving who currently resides in South Africa as an instructor and trainer with the IANTD. Aside from his extraordinary experience level, Shirley is most known for his relationship with David Shaw leading up to Shaw's death in 2005....	South Africa	820 feet	2005

In 2003 Mark Ellyatt is believed to have dived to a depth of 1,032 feet, but that dive has not been independently verified.

All of the foregoing dives were conducted on open circuit SCUBA equipment, except for David Shaw

David Shaw (diver)

David Shaw was an Australian Scuba diving, and an elite technical diving. He is one of Deep diving#Ultra-deep diving who have dived below a depth of 240 meters / 800 feet on Underwater_diving#Diving_with_Self_Contained_Underwater_Breathing_Apparatus_.28SCUBA.29....
, who used a closed-circuit rebreather

Rebreather

Deep diving

Particular problems associated with deep dives

Dealing with depth

Ultra-deep diving

See also

Footnotes

Further reading

External links