Some Comments after Nitrox Certification

[Don Burke]

I believe that people who could understand an explanation of derivation of the formulas are smart enough to figure it out for themselves.

Just looking at the formulas and the tables can be pretty illuminating for someone whose algebra is not too dusty.

 

[MikeFerrara]

... by the posts that I have been reading regarding what should/should not be taught and how/how not to teach it. It seems to me, again, as a novice diver, that an awful lot of the posts (including the original post to this thread) seem to follow the theme of - "The course that I took did not satisfy my personal desire for knowledge, therefore it was inadequate". These posts are invariably followed by two schools of thought, 1) Is so!, and 2) Is not!

So, are the courses inadequate, or are they merely insufficient for some peoples specific experience, education, expectations? My child's 3rd grade science class would be inadequate for a university graduate (hopefully), but are fine for him, and they accomplish their goal of teaching science to a 3rd grader.

PADI lists on their website as the objectives for their nitrox course:

Learn to analyze cylinder contents.
Plan enriched air dives using tables and dive computers.
Safely increase your no stop time.

These seem pretty straightforward, and this is what I am expecting to be able to accomplish when I leave the course. It doesn't say anything about understanding of the theories behind the concept, so I don't think that I'll find the class inadequate if my instructor does not go to great lengths to educate me in it. I imagine that I will want to know more about it (and already do know more about it, since I've been peeking at the theories, computations, and information available here and elsewhere), because I think that it is interesting and relevant to my experience in diving, but, if the goal of the class is merely to safely increase my no stop time (as a recreational diver), didn't they teach what they advertised?

Some good points. Obviously the agency is only obligated to do what they said that they would do.

Today a most consumer can easily check out the PADI web page or come here or any number of other places for all kinds of information. When I started taking diving classes, I didn't have any internet. the only divers that I really knew were at the shop. The shop was my only real-time source of diving information. I thought I was being taught to dive and to understand diving. Being an engineer, I picked up the finer poits of the math and theory myself but it wasn't untill much later that I found out about all the other things that were left out.

 

[MikeFerrara]

Well, I can certainly understand a business or industry wanting to make as much money as possible. But, isn't it potentially counterproductive, assuming that the business or industry wants to stay around, to willfully cut corners on safety, when it's their own customers who they're putting at risk? Certainly, I'd be much less inclined to step on a commercial airline whose planes repeatedly fell from the sky, no matter how cheap and quick their flights were.

As a new diver, how concerned should I be? Am I putting myself at a much greater risk than I believe by following the published guidelines of my training agency? If so, what, if anything, can I do to mitigate the risks, short of not diving at all?

I read the other answer to this but I have a different point of view. I think there is much in the training standards of some agencies that is unsafe. I've gone into it in depth elsewhere on the board but for just one quick example...Do some research on some of the accidents there have been on AOW training dives. Simply, training standards allow an AOW "deep" dive to be conducted while student skills are minimal (WAY inadequate IMO) and possibly with an instructor with very limited experience at that depth...they could actually have none at all. It's actually possible for a student on their 5th lifetime dive and their instructor to do their first 100 ft dive together.

As I see it, what's taught by the recreational agencies might be argueably adequate if, and only if, we assume that divers will be diving at resorts and other such places under supervission. That may be true for many divers but not for all. For the diver who wants to be self/buddy team sufficient and strike out on their own and dive...many of the agency offerings are a total joke and a diver could get much further much faster by skipping those classes all together. Of course, that's hard because you need the card for access (to even get a tank filled). It's the access restrictions that make these classes necessary.
If you want to learn to be a diving tourist and participate in dive tourism, then your local dive shop and it's right out of the book agency classes may work out ok for you. If your interests in diving differs, your local shop probably isn't the best place to look for education. You may certainly find a DIVER who uses his agency affiliations to enable him to issue certifications but the teaching may be a lot different.

As a matter of fact, my basic nitrox instructor was the first such instructor that I lucked into. At the time, the only dive shop within 100 miles of me didn't have nitrox, they didn't use or teach it and they didn't think that any one else should either. There was no mistaking their displeasure when they found out that I was taking a nitrox class in Arkansas (we're in Indiana). We used tables, computers did the math and went diving. He not only used the PADI test, which was a requirement, but he had the IANTD text and others as well as a seletion of different tables. We did some dives that really took advantage of having nitrox but before we did those dives he made sure that I could dive ok shallow.

 

[MikeFerrara]

Now I'll post the alternate version ---- how PADI's course is a joke!

I had a one-on-one nitrox course, and several times I had to explain to the instructor how I calculating things because my formulae didn't match up with the book. I was working from the basics of total pressure and % of gases, using formulae that matched up with the concept rather than using the more calculator friendly, but not so obvious, equation that were in the PADI book.

The original poster mentioned the EAD equation. I clearly remember reverse engineering that equation to figure out what it was doing, and then suddenly exclaiming something like OH! They mean Equivalant Air NITROGEN Depth (the equation figures out depths where ppN2 are the same). The instructor kind of goes Huh? And when I explained the basis of EAD it was the 1st time she had ever heard it explained that way.

Clearly, some further in depth explanations are called for, at least for instructors.

My experience was much the same. My nitrox instructor was pretty sharp but I've helped more than one of my instructors to better understand the math. In my gas blender class I spent as much time at the white board as the instructor. I had already written blending software before ever taking the class (I needed the card) and I did all the math "differently" than it was presented in the text. Of course it made more sense, I could more easily rearange things to answer different questions and so on.

I've never seen a blending text that didn't totally screw up and confuse the math. Of course, now days, blending courses are getting away from the math and relying more on computers too. That's fine maybe except for there are blending questions that can come up in real life applications that I've never seen a blending software able to answer.

 

[MikeFerrara]

A number of posters have suggested that divers who want to know more should take advanced courses. That's fine in some regards but we're talking about the basics here and not something advanced. More advanced courses may include a review of the basics but there are enough new things they need to be learning that it's hard when they need to be learning the basics for the first time.

This is true in the classroom and in the water. I used to teach Advanced nitrox (an entry level "technical" course) and it was a big problem. Students came to me without either the academic or the inwater skill needed to begin learning the new stuff. I'm not the only one who's had that problem. GUE's answer was the fundimentals class. I found that more often than not I had to go back and teach OW level skills before I could start on the stuff that was supposed to be new.

If you don't learn things well at one level, you aren't ready to go to the next. The theory and some of the in-water skills often just aren't taught in such a way as to prepare a student for more advanced training even if they are so inclined. My advice to any one who has more technical interests whether, in the water technical diving or just theory, would be to skip all the "bare bones" course offerings and start your training from day one with an instructor better suited. Of course the problem is that on day one, the student may not know exactly what their interests are or will be. No problem really...you can all the way to DM or instructor, then find out about all the things you weren't taught and go back and start over learning OW level skills in a more functional way. Those divers will end up wishing that they could get all their money back though.

 

[The Chairman]

A better understanding of ideal/non ideal gas laws is essential to fully understanding blending. A college level Chemistry course (may be more than one quarter) will help you to understand these laws as well as to fulfill your desire to learn.

In addition to these, a full understanding of both calculus and physiology are essential to completely understanding decompression theory including the algorythms associated with tables or computers.

Am I too lazy to accomplish all of this? Quite frankly: yes! I have no need to delve this deeply into these disciplines in order to become an "expert". No, I will settle with my current understanding of Gay-Lussacs laws and will continue to learn how to impart enough knowledge to my students to keep them as safe as possible while still having lots of fun.

 

[ianr33]

Nitrox for Dummies:

Dive 32%
. Get the shop to analyze it (analyzers are expensive!)
Set computer to 32%
Do not go below 110 feet

Maybe I should market this as an online course for $50 per person and get rich?