Advanced Nitrox

[Blackwood]

Are you sure?

Yes, though you may be misinterpreting what I mean by "bottom PO₂ range."

If he's on a gas that he only has access to after taking the Advanced Nitrox course (i.e. one containing between 40 and 100 percent oxygen), at 125 feet the PO₂ falls within that range.

 

[dori fish]

I am waiting until january before i take this course b/c that is when I'll get my nitrox but I've seen many take a 30-32% mix

 

[Blackwood]

I am waiting until january before i take this course b/c that is when I'll get my nitrox but I've seen many take a 30-32% mix

Ah, so you aren't nitrox certified.

When you are, you will know that the deeper you go the lower the oxygen fraction you'll be breathing.

Thus, Advanced Nitrox, without the equipment and know-how to switch breathing gases, is of questionable benefit to your dives.

 

[diverdowndude]

Are you sure?

It sounds like this thread should have been named "a Introduction to basic Nitrox formulas,calculations, and principles" How can one seriously consider advanced nitrox training when they are incapable of calculating the MOD of a given mix including Po2 exposure? If you have taken a nitrox course in the past I would highly recommend sitting in on a current class to refresh your understanding of Nitrox and it's intended use. Determining what you would call your acceptable personal exposure to PO2 given age etc. and determining best mix and MOD should be second nature to anyone using Nitrox. If nothing else buy a current copy of a reputable enriched air Nitrox manual from one of the training facilities and pay close attention to the proper use of the formulas in the appendix after reading the material - LOL.

My apologies for being so critical but the fact remains most OC O2 hits prove fatal.......at depth.

 

[peterbj7]

Who is that addressed to?

 

[peterbj7]

Yes, though you may be misinterpreting what I mean by "bottom PO₂ range."
If he's on a gas that he only has access to after taking the Advanced Nitrox course (i.e. one containing between 40 and 100 percent oxygen), at 125 feet the PO₂ falls within that range.

I certainly was misinterpreting what you said, because it is not what I expected anyone would say. You are postulating that someone will take down a rich deco mix and start breathing it as a bottom gas? I must say that I hadn't even considered that as a serious possibility. I don't remember my own training in detail as it was a long time ago, but I do know that then as now it was not possible to be certified by IANTD to use a rich mix without pretty thorough and comprehensive training. I really don't remember what the TDI course requirements were, as although I did all their courses I found the IANTD ones stricter and more challenging. That's why I never submitted my card to be a TDI instructor, though I had done and passed the course in parallel with the IANTD one (whose instructor card I did get).

Any idiot can do a standard recreational nitrox course in just a few hours, grab a tank of 36%, and go down to 130ft using it. Other than perhaps watchful DMs there's nothing to stop it. But we don't gear our courses around that, do we?

Back to the TDI question (because these are only TDI courses) - if someone does Advanced Nitrox but not Deco Procedures are we to assume that they are potentially suicidal?

 

[diverdowndude]

Who is that addressed to?

No one in particular - Given the topic of advanced nitrox I didn't realize the question was being asked by someone considering taking a introduction Nitrox course until after my post - I should have given my reply some thought. Seriously discussing using 40% Nitrox as a breathing mix in excess of 99fsw or 30msw- more specifically 125fsw just didn't sit well - (we lost a diver who was using home brewed .46% in 143fsw thinking he had .25% accident analysis determined he hadn't taken a blender course and failed to subtract the ppo2 from his top off mix.) Nitrox is extremely safe when used properly as statistics show - however unforgiving when used improperly- ie: .40@125fsw. Sorry for the confusion.

 

[Blackwood]

I certainly was misinterpreting what you said, because it is not what I expected anyone would say. You are postulating that someone will take down a rich deco mix and start breathing it as a bottom gas?

No, I'm concluding that the open circuit diver who doesn't switch gases only breathes one gas the entire dive.

In specific, I'm replying to the question about whether Advanced Nitrox is of any benefit to the open circuit, single gas diver running 125 foot profiles.