From: craig@cattnts (Craig Campbell)
Subject: Re: Seeking info on Oxygen Enriched Air (Nitrox)
Organization: AT&T / NCR Canada Ltd., Toronto, Canada
Date: Tue, 14 Apr 1992 14:53:15 GMT

In article <1992Apr7.233104.854@icon.com> malc@icon.com (Malcolm Weir) writes:
>I'm considering the idea of taking a class in the use of Oxygen Enriched
>Air in Sport diving, but am reluctant to spend the money for the class
>until I have a better idea as to what's involved.

>So... What is the collective net.wisdom with regard to oxygen enriched
>air mixes, (e.g. Nitrox, SafeAir, OEA, etc.)?  Is this technique useful,
>useless, safe, dangerous, easy, tricky, A Good Thing, A Bad Thing?
>What about certification agencies (IAND, ANDI, etc.)?  Is one better
>than the other(s)?

Nitrox diving is safer than air diving provided you follow the rules.
Basically, you cannot dive much over 110 ft (round numbers) with Nitrox 
due to oxygen toxicity.  The bennefits of nitrox are 1) shorter decompression
times 2)  a lack/lessening of nitrogen narcosis, and 3)  a lessening of
post dive fatigue.

Nitrox diving requires different tables, although using the air tables would
only give you an added safety margin (as far as I can tell).

You can also calculate your equivalen air depth (EAD) and use any reqular
table you like.

>Will using this stuff with your equipment cause it to vaporize or
>disintegrate?  How about treatment following an accident with it?  Do
>chambers (and their operators) understand it?  Is it only for
>"professional" divers, such as researchers, commercial divers, etc. or is
>appropriate for the sport diver?

Once the tank is filled with nitrox, your regular scuba equipment can be used.
(Note:  I am refering to Nitrox mixes I and II, not custom mixes.)
There is a strong movement to have nitrox pumped ONLY into green and yellow
nitrox tanks.  This is to avoid any confusion as to what a diver is breathing.
(If you thought you were on air, you might unknowingly exceed the maximum
depth.)

>How about cost?  If I need to get special equipment, how much will that
>cost?  Assuming I get certified, how much for a fill?  On that subject,
>how many places throughout the world can provide nitrox fills?

An O2 analyzer is a must for any mixed gas diving.  You MUST know how much
oxygen is present in order to dive safely.  In my part of the world (Toronto,
Canada) Nitrox is difficult/impossible to buy.  You must mix your own, which
requires O2, and O2 cleaned equipment, a booster pump (O2 cleaned), 
O2 cleaned tanks, O2 analyzer, etc.  (No, I haven't got these...$$$$$$)

Hopefully, it is clear that training is not optional.  Until Nitrox can be
purchased pre-mixed, safely, and nitrox tables are well known, don't try
to cut corners.

I hope I have not discouraged you.  Nitrox will most likely become the 
sport diving gas of the future.  Right now though, its just beginning to
emerge, so it is the divers responsibility to take care of himself.

P.S.  The training is not difficult, just necessary.

>Will it cause Contact Lenses to explode? (Sorry, couldn't resist that
>one...  :-) )

I have no idea.

>Malcolm Weir.

Good luck.

P.P.S.  I am toying with the idea of experimenting with trimix.  It is much 
	easyier to mix than nitrox, but requires very specialized decomp 
	tables.  There is a Dr. in Souther Florida who has done extensive
	work wiht mixed gas table, but his name escapes me right now. 
	I believe that Bill Mayne referenced him in an article.  (Bill,
	if you know who I'm talking about, do you have an e-mail address
	for him?  My e-mail to you bounced quite rudely....)

-- 
Craig Campbell		|	These opinions are entirely the result of a 
Systems Engineer	|	small butterfly crashing into the far side
NCR Canada,		|	of the planet.  Chaos Rules.
an AT&T Company		|	I speak for no one, except, possibly, myself.