What is NITROX or ENRICHED
AIR?
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NITROX is a breathing gas that many
SCUBA divers use to extend bottom time and increase safety while diving.
NITROX is simply a mixture of oxygen and nitrogen, but with a higher
concentration of oxygen than normal room air. Air is composed of
approximately 21% oxygen and 79% nitrogen. NITROX, Enriched Air NITROX,
SafeAir, and EANx are names commonly used in the diving community to
refer to oxygen-nitrogen mixtures containing more oxygen than ordinary
air; that is, more than 21% oxygen. There are two standard NITROX
mixtures (originally used by NOAA scientists), NOAA NITROX I with 32%
oxygen and 68% nitrogen, and NOAA NITROX II with 36% oxygen and 64%
nitrogen. In essence, you can start to fine-tune the mixture to
your intended dive profile, enhancing your safety and enjoyment of the
dive. This is called the BEST MIX concept. In even more advanced
classes, such as Technical NITROX, we use very high concentrations (80
% and higher) to aid in decompression.
Why use NITROX ?
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The main benefit to diving with
enriched air mixtures is the reduced amount of nitrogen in the breathing
gas. Nitrogen is an inert gas and is not metabolized by the body.
Nitrogen absorbed in the body during a dive is what usually puts divers
at risk for decompression sickness (DCS), or the bends. Reducing the
amount of nitrogen one breathes can directly reduce the risk of
developing DCS.
Also, I feel much more alert and
"crisp" while diving on NITROX. I am far less tired after a
three or four dive boat trip. Before NITROX, after a long day of diving
and or teaching classes, I would come home very tired, unable to do much
more than just get some sleep. Now its possible to do something in the
evenings. You also have the benefit of INCREASED SAFETY !
Also, using the NITROX mixture EAD
(Equivalent Air Depth ) concept, bottom times can be safely extended.
Because no-decompression limits are based on nitrogen absorption, NITROX
means less nitrogen, which means more bottom time. Many other divers
also report that they feel less fatigued after diving with NITROX
(compared to similar dives using air).
Is there any down side to using
NITROX ?
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The danger of oxygen toxicity,
while present with any breathing mixture (including air deeper than 240
FSW), can become a problem with NITROX due to elevated partial pressures
of oxygen (PO2). This can result in seizures, which are nearly always
fatal underwater with standard SCUBA equipment, as they usually lead to
drowning. This risk can be easily managed by adhering to recommended
maximum operating depths (MOD) for enriched air mixtures. In the NITROX
class, we instruct students on the simple math needed to calculate the
maximum depth for the specific gas you are diving with. There are also
simple tables that also show these M O D's.
What this means in real life is if
you are diving with NITROX 32%, you would simply never go deeper that
130 feet of salt water on that particular dive. This is an absolute rule
that cannot be broken. But in reality, how often do you go that deep
anyway ? And if you NEED to, then grab a cylinder of air.
Another risk related to NITROX is
that of fire or explosion resulting from improper handling and mixing of
NITROX. All cylinders and valves used for partial pressure mixing of
NITROX must be properly cleaned, labeled, and maintained (most
regulators do not need special cleaning unless they will be used with
NITROX mixtures containing more than 40% oxygen). Mixing and cleaning
should only be done by appropriately trained personnel. Again, in real
life this means you buy your NITROX equipment and NITROX fills from a
certified NITROX dive store from a NITROX instructor and you don't have
to worry about these hazards. In the old days, there were a lot of
divers using NITROX with homemade, modified and dangerous equipment and
mixing the gases in their garage ! Those days are long gone, and NITROX
today is extremely safe.
Will use of NITROX reduce air
consumption?
-
Maybe. Probably. The amount of
bottom time you can safely get out of a cylinder is dependant on a wide
variety of factors. Using NITROX may reduce gas consumption. Breathing
rate is primarily controlled by the carbon dioxide levels in the lungs
rather than the oxygen level in the breathing gas. Breathing rate may be
reduced indirectly by NITROX use through other factors, such as
increased comfort level, greater physical stamina and warmth. Also, the
mental clarity or "crispness" you will enjoy may reduce stress
and anxiety sometimes experienced and this will reduce your breathing
rate and gas consumption.
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Can a NITROX diver get bent ?
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Because there is still nitrogen in
the breathing gas, NITROX diving can result in DCS just as air diving
can. Used properly, however, NITROX can greatly reduce the amount of
nitrogen absorbed, thus reducing the risk of developing DCS
substantially.
If a NITROX diver gets bent, can
he/she be treated in a chamber ?
-
Yes, a NITROX diver would go to the
chamber just like any other diver. BUT a diver using NITROX has a
greater chance of beating the bends because of the reduced nitrogen
level than a diver using the same dive profile breathing air.
Will NITROX reduce nitrogen narcosis
?
-
Yes. Because nitrogen narcosis is a
direct result of the increased partial pressure of that gas, diving on
NITROX reduces the effects when compared to diving on air at the same
depth. You are less "narked" on NITROX.
Is NITROX used for deep dives ?
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NITROX is actually limited to even
shallower depths than air due to the increased oxygen content. The
deepest you would want to use a standard NITROX mixture of 32% would be
130 FSW. Other mixtures, such as EAN 26 and EAN 28 can be used deeper,
provided you are certified and trained and equipped to go to those
depths.
Is NITROX safer than air ?
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Yes, we believe so. Used properly,
NITROX has the potential to make dive profiles safer. Also, if we use
NITROX and follow the air dive tables, we are adding up to a 30% safety
margin on our bottom times. Combined with the reduced fatigue and
increased mental alertness, I feel that NITROX is safer than air.
To give both sides of the coin, I
must add that due to the slight additional work in selecting a mix,
filling, and analyzing, as well as the strict observance of an MOD,
there are some that disagree with the idea that NITROX is, overall,
"safer" than air.
We would suggest trying it for
yourself, and you decide. NITROX is the preferred breathing gas.
We use all the latest teaching materials and have the best diving
equipment available for hire.
We send you the course materials before you arrive in Pembrokeshire, then study at your own pace
and get down
to the actual diving sooner when you arrive here !
To confirm bookings we accept credit cards over the phone (Opening
Times); and cheques through the post; usually at least four weeks in
advance of any course or activity. By making any payments clients
consent to have read and agree with our Terms & Conditions. For booking
outside our published schedules and for
any other queries please use
our Contact/Enquiry form, alternatively
the numbers or
email below:
Tel : 01348 871938
Mob: 07816 640684
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ENRICHED
AIR NITROX:
2 dives + theory - 2 days
Including materials and 2 cylinders filled with Nitrox.
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From £
195.-
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