Advanced Nitrox

[Blackwood]

Yes I understand but will advaced nitrox allow you to stay down longer on say a 32% mix and swich to a higher percentage of oxygen on the way up without being considered deco.

Why are you hung up on whether it's considered deco or not? "No decompression" is a misnomer anyway. The dives you are doing now are deco dives. If you're on a (common) 60FPM table, an "NDL" dive to 60 feet calls for one minute of decompression (60 feet takes 1 minute). A dive to 120 feet calls for two minutes of decompression.

 

[Joe21]

It would require the deco class, but Jim Lap answerd my question. Thanks.

 

[peterbj7]

I can't speak for the TDI course as I did it so long ago I've forgotten it, but the IANTD Advanced Nitrox course is better termed "intro tech", as it focuses on equipment handling, stress management and things like that. The "nitrox" aspect of it is almost incidental, though you will learn to use mixes higher than the 40% limit for recreational nitrox. In the case of IANTD the new limit is (or was when I last looked at IANTD Standards) 50%. And of course you take multiple gases down with you and learn to manage gas switching.

If all you want to do is stay down longer for your spear fishing (which incidentally is illegal on scuba in many countries) I don't see much benefit for you. If you want to develop your diving and become a better diver, moving into tech in due course, then it's a great course. I believe the GUE/DIR "Fundamentals" course is broadly similar, though I don't think they'd allow you to use a spear gun.

 

[Joe21]

Cool thanks for the info.

 

[AndyNZ]

The DSAT Apprentic Tec course appears to teach "multiple gas, extended no stop" dives. I interpret this as meaning that you would plan a multilevel dive using one gas at one depth, and another gas shallower.

You may find a instructor who would teach TDI Advanced Nitrox in this way. But put yourself in the situation where you are still at depth, and for some reason your backgas runs out - how tempting is it to switch to a higher O2 (ppO2 >1/6) mix? I personally don't like the idea of "multigas extended no stop" diving. The DSAT syllabus is not overly well thought out, to be honest.

You'll get a lot more out of doing a full tech class (e.g. Adv. Nitrox & Deco. Proc.) and then you can tailor your diving in light of the knowledge you'd gain in the course.

 

[Mr Carcharodon]

Thanks all. I spearfish alot and theres quite a few 100ft and deper ledges up here, but theres hardly any bottom time especially for spearfishing.

If you take advanced nitrox along with deco procedures (a common combination) then the bottom time limitations open up.

 

[Blackwood]

The DSAT Apprentic Tec course appears to teach "multiple gas, extended no stop" dives. I interpret this as meaning that you would plan a multilevel dive using one gas at one depth, and another gas shallower.

I interpret it as wordsmanship to call stage decompression diving something else so it seems less "scary."

If you use a deco gas to "avoid stops," you're accelerating decompression.

 

[peterbj7]

If you take advanced nitrox along with deco procedures (a common combination) then the bottom time limitations open up.

This of course is the TDI terminology. IANTD doesn't have the "Deco Procedures" course (or again, didn't when I was an active instructor).

 

[ianr33]

I interpret it as wordsmanship to call stage decompression diving something else so it seems less "scary."

If you use a deco gas to "avoid stops," you're accelerating decompression.

That gives me a GREAT idea for a new course !

Staged Multiple Mandatory Safety Stop Diver.

 

[AndyNZ]

I interpret it as wordsmanship to call stage decompression diving something else so it seems less "scary."

Possibly! I'd really have to ask a DSAT instructor what they *really* do - Apprentic Tec is a strictly "no deco" course. It could be a mechanism for teaching proper gas switches early on - but in which case why not call it that? I think it's more of a reflection that PADI/DSAT hasn't really thought through it's stance on technical diving training.