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Subject: Mixed Gas Training?????????
Lets see if we can answer the following questions about mixed gas training.
ANS- You seem to be more interested in deep air than mixed gas, it
also seems this is part of an axe you are grinding with
someone, but I will attempt to answer at face value anyway.
1. At what maximum depth should a diver be trained on Air?
ANS- This is a rather moot point since divers go to whatever depth
they feel like and instructors seem to have no standard they
must adhere to.
Take into consideration the following
a. Current suggested PO2 limits (1.6 @Deco gas only) 1.4-1.45 Bottom Gas
ANS- The logical thing would be to apply the same limits to air
that we do to mixed gas. (e.g. 187- 218fsw)
b. Ability of the individual to function in an emergency at suggested depth.
ANS- Too many variables- can't be considered, except on individual basis
c. Possible medical manifestations such as O2 Toxicity and N2 narcosis
ANS- A risk the instructor should be very careful about taking.
d. history of thousands of deep air dives successfully completed between 200
and 300+.
ANS- Many people lost consciousness on these dives. Some retained
their regulator and were rescued by a buddy, Many died on the
spot with little or no warning. There is good reason why deep
diving is on the "big three" of accident analysis. Until very
recently, deep dives were all deep air dives, no choice.
e. Was the reason for these deep air dives because of the lack of mixed gas
training?
ANS- No, all the training in the world will not keep you from
passing out under certain conditions at a certain depth on a
particular day. Many of these divers were quite capable of
training themselves. It was lack of mixed gas technology. Many
divers wanted to use mixed gas, but before the advent of
custom tables the injury rate of cave divers attempting mixed
gas dives was probably way over 50 percent. It was the
appearance of reasonably safe helium tables that caused the
popularity of mixed gas diving.
2. If the diver could NOT complete to satisfaction a deep air course should
he/her be allowed to continue to mixed gas.
ANS- What rationale do you have for thinking that deep air and
mixed gas are related? Except for gas management and deco,
one does not build on the other. It would be equally invalid
to say that one must take a mix course before being allowed
to take deep air. Actually, that might make more sense-.
Take into consideration the following scenario (reality)
A team of 4 divers are planning a dive to 200 feet. The team splits into 2
groups A & B. Team A has extensive deep air dives below 200 feet and chooses
to use Air (just because they want to). Team B does not feel comfortable with
air at 200 so they choose to use a mix of 15%O2 and 25%He to cut the narcosis
and PO2's.
During the dive, the divers on team B become separated. One of the B divers
has an equipment malfunction and is required to breath air from team A's long
hose. Because of the divers lack of experience and inability to use air at
200 problems arise risking the lives of the A team.
ANS- Perhaps these guys are suffering from "tech syndrome" and
have forgotten the basics. Plan your dive and dive your plan.
They decided to make two teams but are still in one group.
This can be very confusing.
a. Should group B divers be trained in deep mixed gas diving because they
are not sufficient on deep air?
ANS- Irrelevant. They should make their dive plan based on what
they can safely do. They should avoid potentially dangerous
situations.
b. Should both teams compromise and use the same gases?
ANS- If they are going to dive together they should have both the
same gas and the same configuration. Otherwise they should
have separate dive plans.
c. Should they each carry additional redundant bottom gas? (another stage
tank)
ANS- Depending on the cave, it is somewhere between a very good
idea and a safety necessity. It's their call.
d. Should they not dive together?
ANS- The decision needs to be made before they meet at the dive
site. If they decide to split, they could invite more divers,
as three man teams may be preferable for deep dives.
e. Would proper gas management save their butts?
ANS- A vague question. Proper technique, equipment and safety
attitude will almost always save your butt.
3. Should there be a minimum number of deep air dives and or years of diving
before you are qualified to take a mixed gas course. (None of this pay as you
go card collecting)
ANS- I wish someone would try to explain why they think deep air
dives would prepare a person for mixed gas training.
I am a firm believer that there should be both dives and
time of Experience between All levels of certification.
a. Has there been a number of fully certified deep mixed gas divers or even
instructors who just Paid the cash for the cards and have very little or no
experience out of the watchful eye of the instructor?
ANS- Certification has been too much downgraded to the level
of "rubber stamp". Many of us believe it is the main reason
there have been so many deaths of certified (cave in
particular) divers lately.
b. How could the instructor know if the diver has (JUST filled in his LOG
BOOK) so he/she may take the course.
ANS- First the instructor has to care. A good instructor knows
what questions to ask. (s)he also reserves the right to
refuse or flunk anyone who is obviously not ready.
. Is there any possible chance of enforcing such certification
requirements?
ANS- In most cases, almost none. That is why it is so important
for All of us to apply peer pressure, to educate, and to
lead by example.
d. Should we as (leaders in our tech diving community) try to sway these
divers into proper training or just continue on our own expeditions and leave
those others alone to do as they please?
ANS- We can't afford to be complacent. It only takes one
inconsiderate buffoon to close a cave to everyone. But we
don't need to be bullies, either. Why should someone who is
already diving to a standard higher than most be expected to
take a course that may be inferior to his own standards?
e. Is the saying true "you cant be a good deep mixed gas diver until your a
good deep air diver"?
ANS- This is a great slogan. There must be some old-time
instructor somewhere spouting this stuff. Perhaps because he
learned on deep air first (no choice), he wants to apply that
experience to everyone else (whether valid or not). It's
got a lovely macho bumper-sticker ambiance to it.
Lets remember that there are many divers out there that are currently diving
extremely deep on air and mix without certification cards. Lets remember that
these individuals have been doing this for along time and will probably
continue to do so no matter what the industry thinks.
ANS- And rightly so. An industry has no right to dictate to us.
The dive industry exists to serve the diver, the diver does
not exist to consume what the industry produces.
Curt @Bowen
Co-Publisher @DeepTech Journal
Whew! now you have a new article for your magazine, Curt,
What are your rates? ;-)
Paul Smith ANS= my answers
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