OW training & cert on Nitrox?

[reefduffer]

On a recent trip I observed something new to me that I'm puzzled about. I was on a boat at a shallow site with several other divers. Along on the trip were a half dozen Open Water students and their instructor. I got the impression the class was not run by the Operator of the boat, but had just contracted for transport to fill up the boat rather than take a separate boat out.

I'm sure it was an OW class, after the second dive the instructor announced we had six newly certified divers. During the dive I also saw them kneeling on the bottom doing skills. What was strange was that all the class were using tanks with Nitrox labels.

Afterwards I made a casual inquiry and was told that yes, they were simultaneously getting their OW and Nitrox certs. I'd been aware of combining Nitrox and AOW, but not OW. I think the agency was PADI, but I'm not certain. I've looked at the PADI website to see if this is described, and at Enriched Air Diver Courses - Scuba Diving Nitrox - PADI Professional Association of Diving Instructors I see:
Ask your PADI Instructor about how you can start your PADI
Enriched Air Diver course during your PADI Open Water Diver course.

Now I acknowledge that even EAN40 ought to be safe wrt ppO2 at the depths an OW diver is "allowed" to go to. And at this particular dive site it would be a challenge to get to 0.6 pp02 on EAN32 (my guess, I didn't ask, and didn't notice MOD or mix markings on the tanks) even with a shovel.

Safety during the OW training with Nitrox itself is not what I'm concerned with. I'll stipulate that's not an issue.

But as rushed, compressed, and stripped of some important stuff as we generally acknowledge OW training to be, why load another set of complications on top of it? I know there were things I was taught during OW that I only really learned later, and I'm not generally considered slow. It seems that doing a Nitrox cert at the same time will just cause some increment of the OW training to be absorbed a little less fully. At the same time, amid all the strangeness of diving for the first time, retention of the Nitrox course information has to be diluted. And this isn't just diving on Nitrox, it's getting certified on Nitrox, presumably all the formal training they will get before doing it on their own.

So both the OW and Nitrox training have to be compromised to some degree by doing them simultaneously. What's the upside? I don't get it. Is a prospective new diver going to be more motivated to undertake OW training by having the combination, presumably more expensive than OW on air?

Would somebody care to explain
- Why this isn't a bad idea.
- Why it exists at all?

 

[MauiScubaSteve]

IANTD has had an Open Water Nitrox Diver cert for some time, since before I became an instructor (spring '01).

While I was in my instructor training one of the Handicap diving agencies visited my IT (Dick Rutkowski) to come up with a similar course.

 

[vtxkev]

I can say that I took my OW, Dry Suit & Nitrox all at the same time. Here is what I noticed about it. I did the classroom & pool sessions of the OW course WITHOUT the drysuit or Nitrox. Then I went back and did the classroom & pool session of the drysuit course. Then finally I went back and did the classroom session of Nitrox. Now once I was ready to do the OW checkout dives I had to actually make 5 dives in total. 4 of them for OW cert and 1 for Drysiut cert. I did NOT have to do any dives with Nitrox although my last dive was with nitrox. Point being is PADI does not require you to dive nitrox to get the cert card. Just pass the written exam and prove to your instructor that you understand. There are no drills with the nitrox to do while underwater. I think its a great idea, it worked for me.

 

[H2Andy]

So both the OW and Nitrox training have to be compromised to some degree by doing them simultaneously.

i see what you're saying, but really, how different is it to learn to dive on 21% as opposed to learning to dive on 21% to 40%?

you'd definetely have to cover the oxtox issues, but that's really the only "new" thing you're introducing to diving with enriched air as opposed to plain air

if the class were a thorough, good class, with enough time set aside to learn dive planning, using the tables, and ox tox issues, i don't see a problem with bumping people up to 40% from the get-go

 

[tep]

I can't speak to combining the classes (OW and Nitrox), but at least one local LDS offers (but does not require) a conservative Nitrox mix for the OW dives for an additional Nitrogen safety margin over air. Diving Nitrox as if it were air, using air tables/computers. Since the max depth is controlled by the local bottom in that area, it seems to be safe enough to me.

You can argue the value of that, but I don't see a safety issue.

 

[reefduffer]

vtxkev: Yes, I know that in Northern Europe/UK and parts of North America where it's pretty much impossible to dive wet, that drysuit cert must be combined. We do what we gotta do, but when it can be separated, I'd think we should prefer it. I learned to drive on a stick shift. I'd strongly recommend that where possible one learns to drive on an automatic, then make the transition. Task loading and all that. But if all you have available is a stick/clutch, it can be done.

And I know that the Nitrox cert can be done without dives. That's completely orthogonal to my point, which is one of information overload in a compressed timeline diluting the effectiveness/retention of both the OW and Nitrox training.

halemano: I can imagine some kinds of handicaps where Nitrox is a useful mitigation for problems. OK. Again, we stretch where we need to stretch.

tep, and H2Andy: I stipulated in my OP that safety during the OW training itself is not an issue. I get that. If they were just diving on EAN32 or EAN40 I'd consider it an interesting curiosity, like the thread a month or so ago (can't find it right now) about some mideast (Red Sea?) Dive OP that only provides something like EAN30 to all divers regardless of cert level.

But they are getting certified on Nitrox, with the only Nitrox training they are likely to ever get, with all the stuff about oxtox and MOD, and they are getting it at the same time as they are being hit with the all the classroom knowledge of OW, and the physical novelty of breathing under water, buoyancy control, skills, equipment, etc..

And H2Andy: "if the class were a thorough, good class, with enough time set aside to learn dive planning, using the tables, and ox tox issues, i don't see a problem with bumping people up to 40% from the get-go"
Uh Huh. And I'm sure the purpose of combining these two certs is to make sure enough time is set aside to learn them both completely.


I'm recapping because the few responses I got were not relevant to the point I was making, so I guess I need to try again. And then this morning, I saw this thread about combining AOW and Nitrox: http://www.scubaboard.com/forums/basic-scuba-discussions/284391-my-wallet-covered-spiders-webs.html
To quote a couple of responses:

My instructor['s] explanation was that [AOW dives] are a special form of the types of diving you are already familiar with. Nitrox includes separate, (slightly)more involved calculations, different tables, and so on. From what I can tell, there is far too much information in a typical Nitrox class to be included in AOW.

And:

...if Nitrox is well taught there is a bit of calculations and some extension of the theoretical undersanding of diving beyond what most new divers are already taught. While for many divers this is a small leap, I have seen some divers that require a significant review of existing information, then quite a bit of work to ensure that they understand the math and theory of the new gas mix implications.

Recognizing that opinions will differ, still, if it's perceived by some as too much to combine AOW and Nitrox certs, how can it be reasonable to combine OW and Nitrox certs?

Please, in the context of nitrox training and certification combined with OW:
- Why is this not a bad idea (exception granted for handicap mitigations).
- Why does it exist at all? What's the benefit?

 

[The Kraken]

But, Andy, don't you know that the greater percent of oxygen causes severe buoyancy issues which can be addressed only after the student has completely mastered hir/her buoyancy control?

the K

 

[vtxkev]

Please, in the context of nitrox training and certification combined with OW:
- Why is this not a bad idea (exception granted for handicap mitigations).
- Why does it exist at all? What's the benefit?

Well here are the obvious answers you are looking for:

- Why is this not a bad idea (exception granted for handicap mitigations). because the dive shops make more money and so does PADI
- Why does it exist at all? What's the benefit? Again so that the dive shop and PADI can make more money off of you at the time you do open water. They tell you that everyone dives Nitrox and you should too. Being a new diver you dont know or have a clue so you say ok and pay them.

Honestly though maybe there are certain people that can task load and do this without a problem. Maybe others can not. I am a new diver and I hear from everyone Plan your Plan & Dive your Dive. To me this means if I am struggling with Nitrox tables to plan my plan then im not ready and not going to dive my dive. Unfortunatly not all people value their life like I do and they think they know it all. So again the only answer to your question is MONEY, isnt that what the world revolves around anyway?

 

[H2Andy]

vtxkev
tep, and H2Andy: I stipulated in my OP that safety during the OW training itself is not an issue.

we agree that learning to dive on enriched air is just as safe as learning to dive on air

But they are getting certified on Nitrox, with the only Nitrox training they are likely to ever get

OW is also the only air training they are ever going to get; what difference does it make if they get 21% only or 21% - 40%? in fact, Nitrox diving would be more complete and thorough training than just air

with all the stuff about oxtox and MOD, and they are getting it at the same time as they are being hit with the all the classroom knowledge of OW, and the physical novelty of breathing under water, buoyancy control, skills, equipment, etc..

again, the only additional thing you'd add would be oxtox issues. doesn't seem like an overload to me.

Uh Huh. And I'm sure the purpose of combining these two certs is to make sure enough time is set aside to learn them both completely.

a bad class on air will be a bad class on Nitrox.

a good class on air will be a good class on Nitrox.

 

[H2Andy]

But, Andy, don't you know that the greater percent of oxygen causes sever buoyancy issues

if you're diving with the Hindenburg strapped to your back?