Why do I need a Nitrox certification?

[ktomlinson]

I was hoping for responses that would be more specific of any realistic danger to me. I understand the basic depth limitations and such. The only mix I use is 32% and as a personal rule I never dive past 110 Ft. I have not studied it closely, but with the aforementioned what specific danger am I putting myself in over air? Also, as a side note, I would put myself in the conservative diver catagory believe it or not.

32% might be fine at 110', but do you know why? Do you know how deep is too deep for 110'? On my dive computer I can set a max po2 that I am comfortable with, do you know what a po2 is and if yes which po2 you are comfortable diving? Being able to answer those questions is a great reason to take the class. Another benefit is that you will learn enough to be able to choose your blend based on the profile of the dive site, which will maximize your no deco time and also get you thinking about things like what happens if in an emergency you dive past 110' on 32%.

 

[chrpai]

32% *might* be fine at 110'. What's your CNS exposure? Do you know what that even is?

32% = 110' isn't a "personal" rule. It's based on some theory that you really, really, really should actually know when breathing enriched air.

BTW, I don't consider you a conservative or safe diver if you are breathing gases that you don't fully understand. Certification or not.

 

[jmneill]

I think you have an excellent point there. I have been diving for about five years, but when I took my OW class I walked away with absolutely no more knowledge than I walked in with. I also watched the instructor pass a student that was unable to take their mask off and clear it underwater. That along with the multiple dive shops that readily dish out Nitrox to anyone that walks up with tank had me feeling there must not be much to it and someone 's just looking to make another $100 bucks for a cert. I appreciate the constructive responses, and think i have gotten what I needed.
Thanks...

Here it is a $99 class...frankly the one I took was pretty horrible and if I hadn't already taught myself about it before class I would have came away from the class knowing which rules I had to follow, but not knowing why.

There have been comments made about why new divers question the need for classes after OW or think that someone is trying to sell them a class they don't need. I'd guess it is because of the way that OW is sold...instead of looking at the classes as credits toward a degree, new divers may feel mislead when they learn that there is much more to diving than OW class teaches them.

---------- Post added April 27th, 2012 at 03:06 PM ----------

 

[diverzach]

You just have to remember F(O2) X the ata of your depth= P(O2). From slight modifications from this equation you can calculate most of the relevant data you need without even having to worry about the computer. If you did go a little past 110' on EAN32 you can see you're not going to convulse, so there really is no increased danger for you. The gas itself is more flammable and if you're not analyzing it yourself you're trusting others that it really is EAN32 and not EAN40. If it was you may convulse after awhile and drown: 4.24 X .4= P(02) of 1.7.

 

[jmneill]

I wondered who the first guy would be to jump on the "conservative diver" thing. Congrats, it's you!!!
Doesn't change the facts though.

32% *might* be fine at 110'. What's your CNS exposure? Do you know what that even is?

32% = 110' isn't a "personal" rule. It's based on some theory that you really, really, really should actually know when breathing enriched air.

BTW, I don't consider you a conservative or safe diver if you are breathing gases that you don't fully understand. Certification or not.

---------- Post added April 27th, 2012 at 03:11 PM ----------

Thank you for the constructive response. This is helpful, and I will get to know it with or without the class.

You just have to remember F(O2) X the ata of your depth= P(O2). From slight modifications from this equation you can calculate most of the relevant data you need without even having to worry about the computer. If you did go a little past 110' on EAN32 you can see you're not going to convulse, so there really is no increased danger for you. The gas itself is more flammable and if you're not analyzing it yourself you're trusting others that it really is EAN32 and not EAN40. If it was you may convulse after awhile and drown: 4.24 X .4= P(02) of 1.7.

 

[Doppler]

So much bad and incomplete information here... wow, it kind of points out the reason that there's a bloody course for this stuff. Anyone here recall that partial pressure of oxygen is only one half of the equation for working out CNS loading?

Anyone remember Oxygen Depth plus Exposure Time = Dose or did you all fall asleep?

And now I'll go back to teaching responsible divers the last portion of their rebreather class.

 

[chrpai]

If you are referring to me, it's because I'm intentionally trying to be vague as I don't want to give the poster a factoid that he then turns into a complete truth.

The OP said 32% at 110. He didn't indicate that he understood the concepts of PPO2 and/or MOD. I was trying to allude to CNS loading without giving him any further ammunition in thinking he knows how to calculate it.

Yes, I remember all of this stuff and I know how to plan and dive a Nitrox dive.

 

[ktomlinson]

You just have to remember F(O2) X the ata of your depth= P(O2). From slight modifications from this equation you can calculate most of the relevant data you need without even having to worry about the computer. If you did go a little past 110' on EAN32 you can see you're not going to convulse, so there really is no increased danger for you. The gas itself is more flammable and if you're not analyzing it yourself you're trusting others that it really is EAN32 and not EAN40. If it was you may convulse after awhile and drown: 4.24 X .4= P(02) of 1.7.

It's great that you know the equation for figuring PO2 (not being sarcastic here), but if the guy doesnt know what a PO2 is, or how to choose one then what will this equation do for him? You shouldn't say that he will not convulse either (I screwed up earlier and posted that 32% at 110' was fine..but there could be reasons that it is not the appropriate choice). I read a study that had one diver that convulsed at 1.3 PO2....so although extremely rare, stuff happens.

 

[Thalassamania]

There is nothing in a nitrox class that could not be learned from careful reading of less than 1,000 words (two sides of a sheet of paper). There is also nothing to be learned by "actually diving it." So why the fuss? Why is nitrox not a normal topic in every entry level course, the critical elements, oxygen toxicity, nitrogen uptake, decompression, etc., are all there with respect to breathing EAN-21, so what needs to be added to extend the knowledge base to EAN-X?

You see, it is not a matter of what needs to be added, but rather what would be reduced, e.g., an extra course charge, an extra book and material sale, an extra certification charge, etc. Add to that the fact that PADI and DAN were four-square against EAN at the start and you'll see why the industry had both face-saving and economic reasons to make sure that nitrox was a separately priced product.

 

[ktomlinson]

So much bad and incomplete information here... wow, it kind of points out the reason that there's a bloody course for this stuff. Anyone here recall that partial pressure of oxygen is only one half of the equation for working out CNS loading?

Anyone remember Oxygen Depth plus Exposure Time = Dose or did you all fall asleep?

And now I'll go back to teaching responsible divers the last portion of their rebreather class.

I'm pretty sure that anyone giving incomplete information is doing so purposely to show the OP that he may have no clue what we are talking about...after all a forum is no where to learn to dive. Why would you assume that people being intentionally vague are incompetent?