| We are breathing
NITROX all of the time.. Air is simply a mix of Nitrogen and Oxygen. in
the ratio 21:79. This must be a good mix for the surface, after
all, nature made it that way. But there is no reason to
assume that it is the best mixture for diving. Having the
ability and expertise to adjust the ratio of oxygen and nitrogen
according to our diving needs is a beautiful thing. |
Nitrox
means deep dives, right?
No, this is definately a myth, Nitrox is more
useful on dives of 100ft deep or shallower and the maximum benefit in terms of
increased bottom time is gained at intermediate depths of about 70 to 100
feet. All Nitrox mixtures including air have a maximum depth at
which they can be used. The larger the percentage of oxygen the
shallower the maximum depth at which it can be used. For
the purposes of recreational Nitrox diving the maximum percentage is 39% which
can be used to a depth of 85ft
Will
I need lots of special equipment?
Special materials and cleaning are needed for any part of your equipment that
comes into contact with a mixture of oxygen that is 40% or greater.
Since this class is limited to mixtures between 21% and 39% Oxygen there is no
need to have a special regulator or BC. You WILL need to have
your tanks and valves cleaned. This is because the valve and the
inside of the tank may come into contact with percentages of Oxygen that are
Higher than 40% during the filling process (not while you are breathing the
tank). If the store you go to uses premixed gases this is not a
problem, however the availability of premixed gas is not guaranteed.
The more traditional and prevalent method is called partial pressure filling
where pure (100%) oxygen is added first and then topped up with air, rather like
mixing a gin and tonic. In this scenario the tank valve comes into
contact with 100% Oxygen. The special cleaning process removes all
particles and any greasy or oily residues from the valve and the inside of the
tank thus minimizing the risks inherent in using 100% Oxygen. The
cost of this cleaning process varies from store to store, locally (in Miami
FL) it can be obtained for something like $25-$40. Once the
tank has been cleaned it will have a sticker on it declaring that it has been
cleaned and can be used for Nitrox. After it has been cleaned you
can still use the tank for air but you must take care that it is always filled
with a Nitrox Ready air supply (we will learn more about these details in class).
I
heard I have to have a computer to dive Nitrox?
It is not necessary to have a computer in order to dive with Nitrox any more
than it is necessary to have a computer to dive with Air.
During the class you will learn how to use both specially designed tables
to dive Nitrox and also you will learn how to use a regular air table to
calculate your Maximum no decompression limits using any mixture of Nitrox from
21% to 40% Oxygen. The advantages and disadvantages of using a
dive computer are the same for both air and other Nitrox mixes.
Is
it true, I will be able to stay down longer if I use Nitrox?
Yes, your no decompression limits are longer using Nitrox. The actual
increase in your bottom time will vary depending on the depth and the mixture of
Nitrox you are Using. In general maximum benefits are between 60 and
100feet. Some examples of this are shown in the table below. But why
is this so? Our bottom time is limited by the amount of nitrogen that is
taken up by our body tissues. Quite simply if there is less
nitrogen in the gas we are breathing then it takes longer for us to absorb the
same amount of amount of nitrogen as we would do if breathing air and our dive
times are increased.
| NO
Stop Dive Times in minutes |
| Depth |
21% |
32% |
36% |
| Fsw |
AIR |
EAN32 |
EAN36 |
| 60 |
55 |
100 |
100 |
| 70 |
45 |
60 |
60 |
| 80 |
35 |
50 |
60 |
| 90 |
25 |
40 |
50 |
| 100 |
22 |
30 |
n/a |
| 110 |
15 |
25 |
n/a |
| 120 |
12 |
n/a |
n/a |
| 130 |
8 |
n/a |
n/a |
Will
I be able to avoid Narcosis if I use Nitrox?
For many years it was believed that the
sole cause of narcosis was the Nitrogen component of the gas mixture.
However; more recent information has shown that the Oxygen component is
also narcotic, therefore in general there is no significant difference in narcosis level
whether you are using Nitrox or Air.
How
much will the class cost?
The cost of the nitrox class depends
on how many people are in the class
If you want a private class it would cost you $250. but if you have a friend(s)
who would like to take the class with you I will only charge $175 for two or
more students.
How
Long will the class take?
Your Nitrox class will consist of eight hours of academic training, including an
exam at the end.
You will then go on a dive trip that will include two dives
This curriculum can be done on a weekend or split into two or three evenings and
one weekend day for the dives.
What
is included in the training?
Gases and Gas Properties
Pressure and Partial Pressure
Oxygen Physiology, Toxicity, and Tolerance
How to pick the best Nitrox Mix for your dive
Decompression Principles
Diving Tables
Using NAUI diving tables with Enriched Air Nitrox
Overview of Gas Mixing
Obtaining and Analyzing Enriched Air Nitrox
Diving Equipment Considerations
Having enought to Breathe and Staying Warm
Contingencies, if things don't go as planned
Technical diving overview.
Not all Nitrox classes are created
equal. For this class you will be required to make two dives WITH me, and
fully plan each dive. One of the dives must be a repetitive dive so that
you will learn to use all of the tables. This is so that you do not wind
up with that lost feeling when you decide to make your first Nitrox dive on your
own. You will already have planned and executed the dives, and will know
how to walk into the store and confidently order your first Nitrox fill.
Where
do we go diving?.
The types of dives we can do will depend on the level of training of you and
your classmates. Ideally the first dive will be between 60 and 100ft
followed by a shallower dive so that you will be planning two different mixes
and experience the maximum benefits. Usually I take people diving on the
fun shipwrecks and reefs off Miami Beach. |