How deep can scuba divers can?

Answer 1

I'm not sure how much is the deepest anyone's ever gone but there is a dive master at my Scuba place who has literally been over 400 feet!!! That's crazy!

318.25 meters without rope stretch by a portuguese guy called Nuno Gomes.

That's 1044 feet and that's also the world record.

To go below or to reach 400 feet depths technical diving training is needed.

I am a dive master and i can only dive to the recreational diving limit that is 40 metres. anything below that is technical diving.

diving that deep for fun is not heroic, its stupid.

Answer 2

The Short Answer - 130 FeetDivers who dive for sport are certified by the recreational training agencies (PADI, NAUI, SSI, BSAC, etc) to depths as deep as 130 feet. Most recreational diving takes place above 100 feet and many regional dive operator organizations, including the Cayman Islands Watersports Association, officially limit dives to 100 feet. In fact, the vast majority recreational dives occur in the relatively shallow depths of 60 feet or less, since most coral and sea life exists above those depths. The Longer Answer - Pretty Darned DeepScuba diving, however, is not limited to recreational diving. Self Contained Underwater Breathing Apparatus (SCUBA) allows technical and commercial diving to depths well in excess of 130 feet. Humans reach a physiological limit of about 210 feet using normal air as a breathing gas. Below this depth, the oxygen in air reaches partial pressures that become toxic. For this reason, deeper dives are accomplished using mixed breathing gases that contain reduced percentages of oxygen.

Deeper depths also increase the risk of decompression illness (also called the "bends"), caused by inert gases (primarily nitrogen) being absorbed by body tissues during prolonged exposure at elevated pressures. Ascending divers require "decompression stops" during ascent to allow time for these absorbed gases to escape from body tissues. It is to avoid these mandatory decompression stops that recreational divers are limited to 130 feet.

In addition to decompression illness, extended exposure to high partial pressures of nitrogen can result in "nitrogen narcosis" which has symptoms similar to alcohol intoxication. To reduce this effect, as well as to mitigate decompression illness, deep dives are often performed using more exotic mixed breathing gases in which both the oxygen and nitrogen percentages are reduced. Trimix 10/70, consisting of 10% oxygen, 70% helium and 20% nitrogen, is often used at depth. The low oxygen percentage of Trimix 10/70 is inadequate to support consciousness in shallow water, requiring divers to switch between multiple cylinders during a dive.

Other environmental factors also contribute to making deeper dives more dangerous. Water tends to filter the shorter wavelengths of light (which is why the ocean appears blue). In shallower depths this filtration limits visibility of red and yelllow objects. The deeper one dives, the more pronounced the loss of light until eventually very little light from the surface remains. Most divers diving below about 60' carry lighting with them.

Temperature is also a concern at deeper depths. Generally speaking, deeper water is colder water. Due to solar heating, water temperature in the first thirty fee or so ranges from about 28F in polar regions to as much as 97F in the tropics. World wide, the average temperature of water in this first surface layer is about 62F. Descending to deeper depths, divers cross barriers, called thermoclines, below which there is very little mixing of solar-heated water. The majority of the world's oceans are below the upper thermocline and average just above freezing at 32F to 33F (Note that salt water typically freezes around 28F). This can make deeper dives very challenging. Divers who spend any time diving deep usually use dry-suits to reduce the risk of hypothermia.

[WARNING: EYE-ROLLING TECHNICAL SECTION FOLLOWS]A brief word about "partial pressure" is in order here. Human metabolic response to breathing gases is based on what is called the "partial pressure" of the gas. Partial pressure is simply the "total pressure", in Atmospheres, times the fractional percentage of the gas. (Don't panic. This is really very easy.) The total pressure at the surface is, by definition, 1 Atmosphere (1 ATM). This means that figuring the partial pressure of each gas in air at the surface is easy. Air is about 21% oxygen, so the partial pressure of oxygen (PPO2) in air at the surface is .21. This is the level of oxygen most humans are used to breathing.

At a depth of 33 feet, the total pressure a diver is dealing with is 2 ATM (Each 33 feet of water "weighs" 1 ATM). So the same air at 33 feet delivers oxygen to the diver at a partial pressure twice as high as it was as the surface, or .42. To the diver, that's the same as breathing a gas with 42% oxygen at the surface. What about 66 feet? Right. 3ATM X .21 = .63 PPO2 -- or a "surface equivalent" of 63%. This means that a gas containing 1/3 the oxygen of air (7%) would be metabolized by the diver at 66 feet as if it was "surface" air, in that it delivers oxygen to the diver at the same .21 PPO2.

The human body can deal with oxygen over quite a wide range of partial pressures. Partial pressures lower than about .12 (surface equivalent of 12%) can result in hypoxia - a condition in which we essentially fall asleep. This is why we can get a bit drowsy on commercial aircraft. Originally aircraft cabin pressure was maintained at a pressure equivalent of 8000 feet AGL (PPO2 about .16). More modern aircraft maintain higher pressures. An Airbus 300 maintains 4500 foot cabin pressures even at very high flight altitudes.

At the higher end of the oxygen partial pressure range, oxygen can become toxic to humans. While the exact onset of oxygen toxicity varies by individual, a good rule of thumb is 1.7 PPO2. That's why the human physiological limit to diving while breathing air is about 210 feet (PPO2 1.55). Central nervous system oxygen toxicity initially manifests itself as seizures, much like epileptic seizures. While not fatal by themselves, oxygen toxicity seizures make it very difficult to keep a scuba regulator in your mouth, so the typical result is drowning.

The Deepest DivesWith the right training, equipment and breathing gas, scuba dives have been made to great depths. The current record for an open circuit scuba dive performed round trip from the surface is 318M (1042 feet). This dive required over 8 hours of decompression stops during the ascent. Scuba equipment has been used at even greater depths for dives from diving bells. Commercial divers have made this type of "saturation" scuba dive to nearly 2000 feet

Late Dutch scientist Johannes Kylstra (1925-2008), began work on the "breathing" of oxygenated liquids in the Netherlands and at Duke University in the 1960s. The fictionalized use of oxygenated fluorocarbon in the movie "The Abyss" was based on actual research done by Kylstra and various military organizations including the United States Navy Experimental Diving Unit. Through replacement of breathing gases with oxygenated fluorocarbons, it is thought that humans will be able to dive to depths in excess of 2000 feet, though no record of any such dive has yet been released to the public.

[Note that all depths listed in "feet" above refer to feet of sea water (FSW)].

Answer 3

I'm not sure how much is the deepest anyone's ever gone but there is a dive master at my Scuba place who has literally been over 400 feet!!! That's crazy!

318.25 meters without rope stretch by a portuguese guy called Nuno Gomes.

That's 1044 feet and that's also the world record.

To go below or to reach 400 feet depths technical diving training is needed.

I am a dive master and i can only dive to the recreational diving limit that is 40 metres. anything below that is technical diving.

diving that deep for fun is not heroic, its stupid.

Answer 4

A record has recently been set at 380 feet without any equipment - at approximately 20 metres a human body becomes negatively buoyant and will sink freely. Ropes are used by free divers to first pull themselves down until free-falling starts, then in turn to pull themselves back to the surface.

Answer 5

For recreational Scuba Diving, we mostly go down to 30m. This is were most of the animals and plat-life are, and also, much further down, and it gets too dark to see much! If you would like to go down further than that, (which is mostly only for scientific work etc) you must get specialist training, and specialist equipment.

Answer 6

This depends on both the divers level of training and the gas they are using. If they are diving on normal air, the maximum depth is about 70m before oxygen begins to become toxic (due to the high partial pressure) but most organisations recommend a maximum depth much less than this (for BSAC they recommend 50m as a maximum).

For professional divers who are using specialist gas mixes and equipment they can dive to hundreds of metres.

The deepest dive on scuba gear was 330m but using a special diving suit, the deepest was over 600m.

Answer 7

It is safe to dive on air down to around 55m, however individuals are limited to certain depths depending on their qualifications and experience. Technical divers can use different gas mixtures which can allow them to go deeper. The depth you travel to also limits your bottom time, so the deeper you go the less time you can spend there.

I have given you what I think is an accurate answer, but I am no expert and someone else more experienced in this area will be able to give you a more accurate answer

Answer 8

The Short Answer - 130 FeetDivers who dive for sport are certified by the recreational training agencies (PADI, NAUI, SSI, BSAC, etc) to depths as deep as 130 feet. Most recreational diving takes place above 100 feet and many regional dive operator organizations, including the Cayman Islands Watersports Association, officially limit dives to 100 feet. In fact, the vast majority recreational dives occur in the relatively shallow depths of 60 feet or less, since most coral and sea life exists above those depths.

The Longer Answer - Pretty Darned DeepScuba diving, however, is not limited to recreational diving. Self Contained Underwater Breathing Apparatus (SCUBA) allows technical and commercial diving to depths well in excess of 130 feet. Humans reach a physiological limit of about 210 feet using normal air as a breathing gas. Below this depth, the oxygen in air reaches partial pressures that become toxic. For this reason, deeper dives are accomplished using mixed breathing gases that contain reduced percentages of oxygen.

Deeper depths also increase the risk of decompression illness (also called the "bends"), caused by inert gases (primarily nitrogen) being absorbed by body tissues during prolonged exposure at elevated pressures. Ascending divers require "decompression stops" during ascent to allow time for these absorbed gases to escape from body tissues. It is to avoid these mandatory decompression stops that recreational divers are limited to 130 feet.

In addition to decompression illness, extended exposure to high partial pressures of nitrogen can result in "nitrogen narcosis" which has symptoms similar to alcohol intoxication. To reduce this effect, as well as to mitigate decompression illness, deep dives are often performed using more exotic mixed breathing gases in which both the oxygen and nitrogen percentages are reduced. Trimix 10/70, consisting of 10% oxygen, 70% helium and 20% nitrogen, is often used at depth. The low oxygen percentage of Trimix 10/70 is inadequate to support consciousness in shallow water, requiring divers to switch between multiple cylinders during a dive.

Other environmental factors also contribute to making deeper dives more dangerous. Water tends to filter the shorter wavelengths of light (which is why the ocean appears blue). In shallower depths this filtration limits visibility of red and yelllow objects. The deeper one dives, the more pronounced the loss of light until eventually very little light from the surface remains. Most divers diving below about 60' carry lighting with them.

Temperature is also a concern at deeper depths. Generally speaking, deeper water is colder water. Due to solar heating, water temperature in the first thirty fee or so ranges from about 28F in polar regions to as much as 97F in the tropics. World wide, the average temperature of water in this first surface layer is about 62F. Descending to deeper depths, divers cross barriers, called thermoclines, below which there is very little mixing of solar-heated water. The majority of the world's oceans are below the upper thermocline and average just above freezing at 32F to 33F (Note that salt water typically freezes around 28F). This can make deeper dives very challenging. Divers who spend any time diving deep usually use dry-suits to reduce the risk of hypothermia.

[WARNING: EYE-ROLLING TECHNICAL SECTION FOLLOWS]A brief word about "partial pressure" is in order here. Human metabolic response to breathing gases is based on what is called the "partial pressure" of the gas. Partial pressure is simply the "total pressure", in Atmospheres, times the fractional percentage of the gas. (Don't panic. This is really very easy.) The total pressure at the surface is, by definition, 1 Atmosphere (1 ATM). This means that figuring the partial pressure of each gas in air at the surface is easy. Air is about 21% oxygen, so the partial pressure of oxygen (PPO2) in air at the surface is .21. This is the level of oxygen most humans are used to breathing.

At a depth of 33 feet, the total pressure a diver is dealing with is 2 ATM (Each 33 feet of water "weighs" 1 ATM). So the same air at 33 feet delivers oxygen to the diver at a partial pressure twice as high as it was as the surface, or .42. To the diver, that's the same as breathing a gas with 42% oxygen at the surface. What about 66 feet? Right. 3ATM X .21 = .63 PPO2 -- or a "surface equivalent" of 63%. This means that a gas containing 1/3 the oxygen of air (7%) would be metabolized by the diver at 66 feet as if it was "surface" air, in that it delivers oxygen to the diver at the same .21 PPO2.

The Deepest DivesWith the right training, equipment and breathing gas, scuba dives have been made to great depths. The current record for an open circuit scuba dive performed round trip from the surface is 318M (1042 feet). This dive required over 8 hours of decompression stops during the ascent. Scuba equipment has been used at even greater depths for dives from diving bells. Commercial divers have made this type of "saturation" scuba dive to nearly 2000 feet

Dutch scientist Johannes Kylstra, now at Duke University, began work on the "breathing" of oxygenated liquids in the 1960s. The oxygenated fluorocarbon used in the movie "The Abyss" was based on research done by Kylstra and various military organizations. Through replacement of breathing gases with oxygenated fluorocarbons, it is thought that humans will be able to dive to depths in excess of 2000 feet, though no record of any such dive has yet been released to the public.

[Note that all depths listed in "feet" above refer to feet of sea water (FSW)].

Answer 9

Experts recommend to never SCUBA dive past 150 feet below the surface of any body of water.