Deep Air Question

[Cave Diver]

cavediver once bubbled...
so why go back to OW 101 and dive air again. you dont have to take deep air to advance to higher levels of diving. what are they trying to show you, that you can go deep be narced, and pay for what you aready know, that air has a narc affect the deeper you go.

Maybe you missed the part in my post where I said that the deep air class was not about diving past recreational limits. The focus on the class is the training in the use of stage and deco bottles, advanced gas planning, and considerations that must be taken into account when diving in the 100' range. Since you skipped this class I take it that you already know all there is to know about these consideration, but for myself I prefer to take every opportunity afforded me to gain knowledge.

 

[MikeFerrara]

Hey everyone,

If we're talking IANTD the course is no longer called "deep air". The title of the course is "Deep Diver". We usually combine this class with Advanced Nitrox or if the diver hasn't had Nitrox yet it can be combined with Nitrox. The max depth is 130. The purpose is to introduce the equipment, skills and plannind required for deep/tech diving. The instructor can give credit for experience but I would have to check the standards to see just what he can do. For most divers to skip this course and go streight to trimix would be impossible. Not because of the gas but because of the skills. The Deep Diver/Advanced Nitrox is often a real shocker. Someone like WreckWriter who has many deep dives in doubles may pull it off. However, there are not many of those.

I have yet to complete a Deep Diver/Advanced Nitrox course in the minimum number of dives. The course is not about the depth, it is about the skills. Once you have Advance Nitrox you can take a combination of the Technical diver and Normoxic trimix and thus never exceed 130 without Helium. You can skip Normoxic trimix (once called intermediate trimix) and go streight to full/advanced trimix however you can't skip the technical diver course (once called technical nitrox). This class taken alone does require you to go past 130 without trimix. Again what credit an instructor can give for experience I'm not sure. IANTD is much smaller than an agency like PADI. I have heard of exceptions being made but they may require getting the ok from Tom or David Mount.

 

[-BlueHole-]

How deep is deep ?
Depends on too many factors...
in a lake with 5 mt. of visibility and a temp of 4 Celsius 120-140 feets could be deep (on air)
in the sea with 30+mt visib and 20+Celsius 120-140 is not deep
is warmer--breathe less, you see--less stress, so less narcosis less co2 retention, also po2 becomes not so (but remains) dangerous...
probably a warm-clear sea diver will feel more the depth in a lake, and a cold-dark lake diver will feel lees the depth in the sea...

 

[hitomi316]

i find that Bluehole gave me something to think about. Planning on diving "up north" this fall.............glad you gave me another angle to plan my dives!!:book2:

 

[DocRCH]

I'm sorta late getting into this thread.The narcosis of deep air and N20 are essentially the same. Currently, the Myer Overton theory of how anesthetic gasses work goes on the basis of lipid solubility of the gas in question. It is thought to make the electrical conduction to be inhibited somewhat. To me, this is a logical description and the data and mechanism seem to "fit". (There is a competing theory with the activity occuring at the synapse. But, this is academic.) Helium is also an inert gas (as far as the biological systems go) and it is used to prevent narcosis. It is not as nearly as lipid soluble as N2 or the anesthetic gasses. As far as diving, I would think that N20 at any depth would be ill advised. Maybe, on the boat after the dive.... just kidding!

Robert:doctor: