nitrox class question (PADI or IANTD)

[Dragon2115]

Sounds more like an "issue" with that particular dive shop.

 

[StSomewhere]

Let me tackle these out of order:

do i need a nitrox class? or do i save my tuition for gear/ rescue course?

No, you don't need a Nitrox class but yes, you probably want one. The thing is, for recreational diving the advantages of Nitrox aren't always all that obvious.

First would be if you either sip air or have more air with you than the stock AL80, you'll definitely get longer NDL times with Nitrox. Depending on depth, even half again as much NDL times.

Second would be (even with the smallish AL80 tanks) if you were doing repetitive dives, like at a dive resort or on a liveaboard. You'll be able to do shorter SIs and longer second, third, and fourth dives with Nitrox. This is the main reason why you should take a Nitrox class sooner rather than later.

Last, some people claim to feel better after diving Nitrox vs. air, esp. if you can slow down that final ascent rate (the last 15-20 ft).

was thinking my options for a nitrox course: PADI vs. IANTD

IANTD offers training (at a local LDS) with doubles... it's a slightly more expensive course so it's no major factor. factor is this: i'd really like to be able to learn to use doubles although i do not foresee myself getting to use double on any type of regularity as my targetted bouyancy system setup is BC rather than a BP/wing or similar doubles-friendlier setup

I don't think you need to dive doubles to learn Nitrox, though there is an obvious advantage to the extra gas. And it might be nice to learn to initially deal with doubles under supervision. But as I said above, the prinicpal advantage will be with repetitive dives. And you don't need (or maybe even want) doubles for that. And a BP/W doesn't necessarily mean doubles. The IANTD *Advanced* Nitrox course should be done with doubles or an H-valve since its more of a tech class, but doubles are really unncessary for the first IANTD Nitrox class, IMO.

You really don't even need to do the dives for the dives for this class. Its more about being able to execute a dive plan. Specifically, you need to be able to develop a sane dive plan, pick the right gas (pPO2/MOD) for that plan, be able analyze that gas, and be able to execute that dive plan with that gas. All on your own. And that's good practice even for your dives on (gasp!) air.

so is it a practical thing to learn? is the extra expense worth it given the realities of my dive situation/s? would love to hear from guys who have undergone (or are familiar with) either (or both!) training curricula

My IANTD class was very practical and informative, and very much worth the time and money.

As for the PADI vs. IANTD debate, I initially got the PADI materials and thought they were definitely lacking (read: crap) compared to the IANTD workbook or even Rob Rossier's Recreational Nitrox Diving book. For example, no where do the PADI materials teach you how to calculate "best mix". Umm, that's kind of an important number to be able to back into if you know how deep your potential dive sites will be.

PADI also relies too heavily on their tables and conversions back and fourth, unfortunately at the expense of understanding. Tables are fine but you should understand the "why" of the numbers, not just the "how" of manipulating between the PADI RDP/EAN/EAD tables. Besides I've never understood how PADI can be so table oriented and still use that kludgy RDP. You'd probably have to see how straight forward using the IANTD tables are (esp. if you are using different EAN mixes for different dive depths) to know what I'm talking about.

My advice would be (1) to take a Nitrox class, and (2) take the IANTD EAN class, and (3) insist that you be able to do the dives with whatever equipment you'll be using in the near future. In the big picture it'll definitely be worth it.

 

[StSomewhere]

IANTD.

We learned something interesting last year. IANTD certification allows for a max PPO of 1.6 while PADI only certifies for 1.4 (I am sure that this is not worded well, but I know what I mean!) On a dive, my buddy and I were allowed to dive a different profile because we were IANTD certified, so we were allowed to exceed 1.4 All the other divers certified by other organizations were limited to 1.4 and had a shallower shorter dive.

Correction. IANTD actually teaches that the pPO2 limits are meaningless without respect to time of exposure.

Off the top of my head, the maximum CNS exposure limit for a 1.6 pPO2 dive under perfect conditions is 45 minutes. So the very max you should dive on a single non-working, no-current, non-cold, well-hydrated-fit-diver dive at 1.6 would be 45 minutes. If you were going to be down longer then you'd already need to adjust for your pPO2 range, and that's still under perfect conditions. You'd probably want to build in some contigency into your plan.

So instead of saying your MOD should only ever be based on a pPO2 of 1.4 like the other agencies do, IANTD training says you should use your brain and actually be responsible for accounting for all the variables.

 

[MEL-DC Diver]

StSomewhere,
I agree with you about the PADI Nitrox. I am taking it right now and am wishing that I took IANTD. You are spot on about not teaching about how to calculate the best mix - you have to learn how to figure this out for yourself - not a big deal, but you'd think it would be covered. While I think they cover the basics very well, they provide 'special' RDPs for EANx32 and EANx36, which if you use and end up changing your mix on a second dive to anything but those two, will screw you up a little bit, since those RDPs are 'optimized' for time and pPO2. Better to stick with a single method. When I was doing my exercises, I took me a little while to figure out that those RDPs were screwing me up.

Also, I heard that IANTD does not recognize the PADI Nitrox (not sure about this), but if true would mean that you would have to start from scratch if you wanted to pursue the Tech route with IANTD.

 

[Kim]

OK I'm biased - I did IANTD.

If I had to do it again I'd choose IANTD again.

 

[sweatfrog]

I heard that IANTD does not recognize the PADI Nitrox (not sure about this), but if true would mean that you would have to start from scratch if you wanted to pursue the Tech route with IANTD.

Now thats just plain wrong. There are plenty of PADI/IANTD Instructors. Each one makes their own decision about certification and good ones teach all the relevent information.

 

[MEL-DC Diver]

Now thats just plain wrong. There are plenty of PADI/IANTD Instructors. Each one makes their own decision about certification and good ones teach all the relevent information.

Well, that's why I added the caveat 'not sure about this'. Anyway, I just learned that it is not the case this past weekend. My theory was taught by a PADI instructor and that was his thinking. Due to scheduling difficulties I did my dives with a PADI/IANTD instuctor and he set me straight. The good news is that I ended up, as you said, learning the relevant information from both organizations. The IANTD triangle calculation I found especially useful.

Anyway, I ended up (as of yesterday) getting cross-certified and am now IANTD and PADI Nitrox certified - not that you have to be both - just makes me feel special :king:

 

[StSomewhere]

Any IANTD instructor worth his or her salt -- and I'd say that's most of them -- would want to test what you actually learned in your PADI nitrox class to make sure you were up-to-speed, that there weren't any knowledge gaps. I've interviewed a half dozen IANTD instructors for future certs and have yet to find one that was actually anti-PADI (and my OW was with PADI, due to geographical limitations).