Some Comments after Nitrox Certification

[TSandM]

I want to start by saying that, in case anybody doesn't know it, I'm in the same camp as the OP. I want to know the WHY, and drove my OW instructors crazy with it.

That said, I've done PADI classes through Rescue, and NAUI Nitrox, and one of the comments I immediately made about the NAUI class was how much better, and better written, I thought the Nitrox teaching materials were than anything I had gotten from PADI. Although not written at the level that would excite me (but I majored in math), it was still thorough enough, and had enough theoretical underpinning, to make me feel as though it was a very legitimate class.

There's a fairly current thread from someone who took ADVANCED Nitrox and felt the same way. The problem is that there doesn't appear to be any class that teaches what I (and I suspect the OP) want to know about this stuff, or if there is, it's so far up the technical diving ladder that our actual DIVING skills won't let us take it. Thus my burgeoning library of books and downloaded documents . . .

 

[Packhorse]

Im starting a nitrox course in the next few weeks, so Im trying to lean as much as I can before. Although I would rather just do an advance nitrox couse but have to do a standard course first. Seems a bit pointless having to learn it all twice. But any way I have a few questions
What does EAD stand for? equivilant air depth??
Is this formula ((D + 33) FN2/0.79)-33 = EAD used for caculating NDL on air tables while diving Nitrox?
Is the metric version ((D+10)xFN/0.79)-10= EAD ?
So if I dive to 30m on 32% EAN and I didnt have nitrox tables I could use air tables for 24.4 meters? And my PPO of 02 would be 1.28? and PPO for N would be 2.72?

Its OK this page answered all my questions.

http://www.gasdiving.co.uk/pages/misc/Nitrox.htm

 

[The Chairman]

The problem is that there doesn't appear to be any class that teaches what I (and I suspect the OP) want to know about this stuff, or if there is, it's so far up the technical diving ladder that our actual DIVING skills won't let us take it. Thus my burgeoning library of books and downloaded documents . . .

You're in luck: http://www.gk2006.org/

 

[theatis]

Lots of interesting replies and too many to comment on individually but a few hit the nail on the head of what I'm trying to convey and in addition things that I'm implying and haven't explicitly stated.

I don't know if Mike Ferrara was specifically referring to me when he said that there are students who simply want to learn more without going tec but that's exactly the point. An aspect of this learning process that we all seem to go through that I find a little bit problematic is that many treat the tec-rec distinction as a mutually exclusive dichotomy. So, the result is, when someone says 'I'd like to learn more about this' the answer invariably is 'go become a technical diver'. Well, speaking for myself, maybe I will, maybe I won't, who knows how I will progress in the future? But for now, I'd like to have as much information available so that when the time comes to make those decisions, they will be as informed as possible.

TSandM's point is also exactly along the lines of my argument and concerns, I'm not yet skilled enough to be a tech diver, but does that make me incapable of learning more?

Of course, NetDoc's point about the imposition of standards is well taken; in no way am I trying to argue for some drastic (and highly unrealistic) raising of standards to prohibitive levels.

 

[MikeFerrara]

Theory VS Practical Application.

Which is more important? How much theory is essential for the safe execution of a NitrOx dive?

They go together. Theory supports practical application.

Do we need to understand gas kinetics, or maybe decompression theory and physiology? How much do we need to understand? How much CAN we understand?

Good question. I don't think the best answer is at either extreme.

More importantly, do we feel that EVERYONE should be taught our way or no way at all? Do we have the right to impose our standards of diving on everyone else?

Think about it. There are many who want an easy course and there are those who abhor it. To each his own.

No, not everyone should be taught my way ot your way. There are lots of divers like me who don't like to just memorize rules. I need to know more about how things work for it all to come together.

When I was actively teaching, I had all kinds of students. I had some who probably couldn't have balanced their check book without help but I also had lots of very sharp, educated students who wanted to know more. I'm pleased that I was able to provide it. I've had instructors who couldn't. Fortunately I didn't need them to teach it to me but that made buying the card simply paying for access too.

 

[MikeFerrara]

I haven't taken any Tec Classes, but I have a feeling that they are very labor intensive and require you learn the material and theory behind it. Tec Divers have a thirst for extending their knowledge in the sport or need to dive commercially so this acts like dive training for them.

Tech classes are sometimes kind of light on the math also. That's especially true for blending courses. I haven't ever seen a text where they didn't hose the math up. Oh...the way they present the equations will work for the specific applications they provide but they're hard to understand and hard to rearange to answer other questions. Here too, I had to it myself. That's fine but what did the instructor do to earn his pay? I think my blending students got a better class because of it and it sure has helped me when I had to spend a week in the field mixing gas for 5 divers and trying to stretch the gas as far as it would go.

In this sport, like many others, people don't care about theory and reasoning behind everything, they just want to dive and get in the water.

-Kstnbike

Again, this is certainly true for some but not all. Some take a class and then complain that they didn't need the class for what they got. I feel that way about almost every diving or dive related course that I've taken. All but a very small handful were pretty lame.
_____________________

 

[MikeFerrara]

I didn't notice any comments on the EAD explaination that I gave in answer to the original post. Did it answer the question? Were there any parts that weren't clear?

 

[MikeFerrara]

As far as the theory presentation for a nitrox class, I always liked the way the IANTD texts presented it about the best. The use the circle devided into three parts with "gas pressure" above and "pressure" and gas "fraction" below. If you haven't seen it, it might be hard to picture from my descroption but it's a nice graphical representation that clearly shows the relation ship and how to rearange the equation to solve for any quantity you need. With most students it doesn't require any explaination at all and at worst it takes a couple of minutes to explain. It's so simple and useful that I can't see any advantage in not teaching it. How many seconds do we need to shave from the class? Though it's not in the book, with a couple of extra minutes I can show how that same graphic can be used to pull out EAD or to remember how to. Wam-Bam-thank you mam and you have all the math that you'd ever need to support a complete nitrox class and you can go on to messing around trying to navigate computer screens or whatever. Better yet, take the class diving and see if they can do it all when it counts.

 

[miketsp]

..snip..
How much do we need to understand? How much CAN we understand?

More importantly, do we feel that EVERYONE should be taught our way or no way at all?
..snip..

Reminds me of an amusing incident in our Nitrox class.
The instructor had just completed one of the theoretical parts which to myself (engineer) and 3 other students (engineers) were quite straightforward. However my wife and some others were lost and had no idea what was going on. So I stood up and tried to help with an explanation. Still blank faces. Two of the other engineers in turn stood up and tried to clarify the subject. Still blank faces. Then this psychologist stood up and explained the subject in a convoluted way that made us engineers shudder with horror. When he finished and I looked around, all I could see were smiles. All the non-engineers in the room now understood the principles of partial pressures and variation with depth.
There's probably a moral here somewhere...

 

[chrisch]

How to dive nitrox for recreational divers.

1. Get the guy in the dive shop to analyse the gas with the shop's analyser.
2. Look up the MOD on your slate.
3. Set your computer to the O2 percentage.
4. Go dive. Do not exceed the MOD

Now which bit did you say wasn't covered in your course?

Chris