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! Warning:Scuba diving is a safe hobby, but without proper training, equipment and attitude it may endanger yours and your dive buddy's life. The author takes NO responsibility about the information of this page.
I've gathered some information about exotic diving gases to this page, which are very rarely used in diving.
Heliox is a mixture of helium and oxygen (HELIum-OXygen). Heliox is used on deeper dives than it's possible to dive with regular air.
Hydreliox is a mixture of hydrogen, oxygen and helium (hydrox = hydrogen + oxygen). Neox is a mixture of neon and oxygen. Neoquad is a mixture of four gases: helium, neon, nitrogen and oxygen. Argox is a mixture of argon and oxygen. These gases are very exotic and rare diving gases. These gases are used mostly in scientific research or in commercial diving.
Hydrogen has been used succesfully in extremely deep dives (500 meters and more) with helium and oxygen.
The COMEX (France) have studied the effects on divers of exposure to hydrogen-helium-oxygen at chamber depths to 2300 feet (701 m)
(performed in 1992, test name: "HYDRA 10"), 1706 feet (520m) and in the ocean 1752 feet / 534m (performed in 1988, test name: "HYDRA 8").
The mixture of these three gases is called hydreliox. Logically, it doesn't really have any benefits to diving with open circuit SCUBA
equipment (since it's not very good idea to dive to such depths, mentioden above, with OC...). More about COMEX's dives:
Neon is less absorbed by body tissues than helium or nitrogen due to it's greater density, but it's also very expensive gas compared even to
expensive helium. Instead of pure neon, there has also been use for crude neon mix, which is a mixture of 75% neon and 25% helium (crude
neon is a by-product in air distillation). Neon as an inert gas seems not to have any narcotic effects in a dives less than 360 m depth, and it
does not cause the distortion of voice like helium or hydrogen does. The density of neon limits it still mainly to depths less than 180 m, because
neon is so slowly released from body tissues causing long decompression times. This is the reason why neon is mostly used in a short bounce-dives.
Neon is mostly used together with oxygen (NEon+OXygen = "neox"), or with trimix (trimix = helium + oxygen + nitrogen) to make neoquad mix.
DCS cases, where diver has breathed neon as an inert gas, are very hard to treat because of complex recompression schedules.
Argon is very narcotic gas (much more narcotic than nitrogen) and also very dense gas leading to breathing difficulties
on very deep dives, but it does not cause the distortion of voice like helium or hydrogen does. In theory argon could
be used as an decompression gas on shallow depths together with oxygen (argon + oxygen = "argox",
argon+O2+N2 = "argonox") to reduce the inert gas absorbance into tissues on ~ 9-15 m decompression
stops. Argox/argonox is not suitable for deeper dives due to the high narcotic effects.
While regular gases like air, oxygen, nitrox and trimix are used in technical diving commonly, exotic gases mentioned above are very rare. However, there are still numerous gases which are theoretically possible for inert gas use. Some of them are listed below.
Xenon (Xe) is a noble gas and non-toxic, therefore it could be used as an inert gas in breathing mixture together with oxygen (xenonox), but xenon is also very narcotic gas (it's an anesthesic gas too...) and that's why there's no real use for diving. Xenon is actually 25 times as narcotic as nitrogen. For a dry suit gas xenon could be nice, because it has very good thermal characteristics, but is has not been tested for that purpose enough. Xenon is also very, very expensive gas!
Krypton (Kr) (oxygen + krypton = kryptonox) causes dizziness, and it's not suitable for diving. Radon (Rn) is radioactive gas, and obviously not suitable for diving.
Krypton is a noble gas, but not suitable for diving use. Krypton (Kr) (oxygen + krypton = kryptonox) causes dizziness. Krypton is also very expensive gas.
Radon (Rn) is the heaviest gas, and chemically it is completely inert. However, it is radioactive (its longest lived isotope has a half-life of only 3.8 days), and obviously not suitable for diving. By numbers only, radon could be good choice for dry suit inflation gas because of it's great thermal insulation properties.
Isotopes of a chemical element are atoms whose nuclei have the same atomic number (Z),
but different atomic weights (A). The word isotope meaning at the same place, refers
to the fact that isotopes are located at the same place on the periodic table.
Deuterium (H22) is a heavier isotope of normal hydrogen (protium, H12), but too expensive to use in diving.
Liquid breathing (fluid breathing) is only performed in scientific research studies and medical treatments. The fluid, which is used in breathing,
is called "LiquiVent®". There are plenty of information available in the Internet:
About the "Abyss" movie: http://www.scienceweb.org/movies/abyss.html
Bibliography about liquid breathing: http://www.mindspring.com/~divegeek/biblios/liquid.htm
Narcotic factors of gases:
(Chemical sign, name, factors (divide by / multiply by) )
He, helium, 4.26 / 0.23
Ne, neon, 3.58 / 0.28
H2, hydrogen, 1.83 / 0.55
N2, nitrogen, 1 / 1
Ar, argon, 0.43 / 2.33
Kr, krypton, 0.14 / 7.14
Xe, xenon, 0.039 / 25.64
(Source: "The Physiology and Medicine of Diving" by Peter Bennett and David Elliott, 4th edition, 1993, W.B.Saunders Company Ltd, London.)
The table above is based on narcotic effect of air (=1). So, for example,
xenon (as diluent gas in same percentage as nitrogen in air) in breathing mix is 25.64
times as narcotic as nitrogen. Or helium is 4.26 times less narcotic than nitrogen, etc.
It is also good to know, than oxygen is narcotic in high partial pressures. Some sources claim it to be as narcotic than nitrogen (Bill Hamilton, http://www.tekniskdykking.org/tekniskdykking/artikler/aqua/RWHNitrox.htm.
|gas||chem. sign / ingredients||use||price.:
(10ltr*200bar) (Finnish price converted to US dollars)
0,9%Ar, 0,2% other
|common diving gas||~$ 5||compressed air is the most common gas for diving|
|nitrox||oxygen (O2) and nitrogen (N2) mixture||hyperoxic nitrox: see below: EANx.
hypoxic nitrox: longer bottom times on 50-60 m dives. This gas was used mainly decades ago on commercial dives. Oxygen percentage is less than 21%.
|hypoxic nitrox gives you stronger nitrogen narcosis and longer decompression, but it reduces the CNS% load|
|EANx / enriched air||oxygen (O2) and nitrogen (N2) mixture||oxygen percentage more than 21%||~ $6-15||commonly used|
|oxygen||O2||decompression gas||~ $8-15||maximum diving depth 6 m|
|trimix||oxygen (O2), nitrogen (N2) and helium (He) mixture||deep diving gas||~ $8-100 depending of helium percentage||used on deep dives for reducing the partial pressure of oxygen and nitrogen narcosis|
|heliox||oxygen (O2) and helium (He) mixture||deep diving gas||~ $50-100||used on deep dives for reducing the partial pressure of oxygen and nitrogen narcosis|
|argon||Ar||dry suit gas||~ $10-30||dry suit gas, mostly used with trimix (which is not suitable for dry suit gas due to it's high thermal conductivity)|
|argox||oxygen (O2) and argon (Ar) mixture||decompression gas||~ $10-30||used on ~9-15 m decompression stops, see above "argox"|
|hydrox||oxygen (O2) and hydrogen (H2) mixture||deep diving gas||? $||explosive, mixture not breathable above 30 meters|
|hydreliox||oxygen (O2), heliumin (He) and hydrogen (H2) mixture||deep diving gas||? $||explosive, mixture not breathable on shallow waters|
|neox||oxygen (O2) and neon (Ne) mixture||deep diving gas||~ $2000||rarely used, very expensive|
|neoquad||trimix and neon mixture||deep diving gas||~ $2000||rarely used, very expensive|
|xenon||pure xenon (Xe)||N/A, (dry suit gas?)||~ $4500||very good thermal insulator, but too expensive|
|xenonox||xenon (Xe) and oxygen mixture||useless for diving||~ $4500||extremely narcotic|
|kryptonox||krypton (Kr) and oxygen mixture||useless for diving||~ $8000||extremely narcotic|
There is not really training courses for exotic diving gases, which are described in this page. Diving with hydrogen or neon is very rare, mostly commercial or related to some sort of experiences (and though dangerous...). Training courses for other gases than ordinary air:
Training agencies for nitrox and trimix diving:
For example: Tech Diver 1-3 courses.
Basic Nitrox Diver, Advanced Nitrox Diver, Technical Diver, Normoxic Trimix Diver and Trimix Diver courses.
Tec Deep Diver and Tec Trimix Diver course.
Enriched Air Nitrox Diver Specialty course.
Making your own decompression schedules requires thorough understanding of
decompression theory and inert gas properties. There are several web-based
decompression tables for air and nitrox diving. Nowadays, several decompression
software include helium.
You may try Google with keywords "decompression software" and see how
many links to different deco SW there are!
However, not many decompression software include exotic gases, like neon or argon. I'm not aware of any software that includes krypton, xenon or others strange gases (and there is really no need for them, too..).
Departure decompression software has neon option too (in addition to air, nitrox, heliox or trimix dive planning).
For argon, Abyssmal's Abyss decompression software included it, but the SW manufacturer's website is not anymore working. See this image and company's web site.