Deep Diving on Air

[Doppler]

Just a brief note about an observation made that may counter the adaptation argument.

Many years ago, and on mix, I had an opportunity to look at some line put down in a deep cave (around 300 feet) by Sheck Exley. It was supposed to follow the "gold-line" path. Instead it ran close to perpendicular to that pathway... directly into a pile of silt and a wall. It had been left in place to illustrate a point. My guess is that you get that point.

There may be a level of narcotic loading that one is able to deal with... the effects of nitrogen partial pressure are what they are and perhaps it is the other contributing factors that we can work around... in any event, there does come a point where narcosis wins... every time... even if you are used to diving with a buzz on.

 

[MXGratefulDiver]

To get there is where danger comes in, Feb 19 2012 an instructor failed at a AOW class at alki beach here in seattle a cold water diving destination to teach proper deep diving and sadly that diver Died. What is worse yet the tank had 700 psi in it. That instructor had no Idea what he was doing or aware of his student, plus a first drysuit dive for the student.

You've made this accusation before, and it was deleted. However, it's in a different forum now with different rules so I'll ask nicely ...

How do you know the instructor failed to teach proper deep diving? How do you know the instructor had no idea what he was doing?

To my knowledge ... having spoken with people who were involved in the recovery of the casualty ... there is no indication that the instructor did anything irresponsible or outside the scope of what his agency standards dictate.

Can you elaborate on what you think he did wrong?

... Bob (Grateful Diver)

 

[billgraham]

Forget Narcosis... Doesn't "air" become toxic below 220 ft? 21%o2 @ 220 = 1.61 PPo2. How are people diving 400 feet on air and not getting a tox hit?

Thank you for doing this first. Dalton's diamond is your friend, don't ignore it.

 

[vcblklion]

It is always interesting to see the posts on SB. I do understand the concern that some have about diving below the rec limits and I do not advocate making it a habit, however, I do think that many people do dive below the limits (drop dives of less than 3 minutes below 150 feet). I was only trying to gauge how often people ventured out of their comfort zone and went deep on air.

The issue that I have with not exploring or discussing diving deeper is that people are afraid to dive to 130 feet, and in an emergency would be afraid to go deeper. From what I have read on the "internets", diving air to 165 feet on air is reasonable with the right education and a trained individual. The French have levels of diving that sets a limit on diving of 165 feet on air. The world's record on air is in excess of 450 ft, but that is crazy.

While I am in favor of having respect for the dangers of deep diving, I am not a fan of fear in diving. In the past I would feel anxious about my diving to 130 ft, now I think that anxiety will be much less since I have seen what it is like below that level. I again would not promote the activity but suspect that there are many divers who dive down to 200 ft on air and not infrequently.

Wow.....dude....all I can say is "clueless".....how about we jump out of a plane without a parachute....just to see if we can make it...? geez....

 

[vcblklion]

I'm not sure that I get the significance of many of the posts, in that, I do not equate a dive to 165 ft to that of 225 ft or certainly 300 ft. The specific issue of exceeding the ATA of 1.6 that occurs deeper than 200 ft would seem to be something that does not come into play at 165 ft. Yet, there is little differentiation of these points on most posts. The only thing I take away from most posts is >130 ft = evil and death.

Well then my freind you have missed the point of most of these posts....I understood from the gist of these posts that >130 ft (WITHOUT THE PROPER EQUIPMENT AND TRAINING) = evil and death

 

[vcblklion]

Well another diver in training died looks like instructors for new divers need some training, or is that all you can do is whine your way on post.

If a Deep Air thread can go without NWG or BJ arguing over how much they are against and there way is the best. But they wont let it go long enough to let it happen.

Well I know one thing I have enough experience in deep air diving, I do it almost every day I can and in the last 6 months I have been doing a bounce dive like I did today. Done several deep air dives in a day, and I clean my gear, fill tanks, and come on SB and constantly am reading how BJ puts me down on other threads and post. To be honest from reading his post he does not know how to dive all that well.

It does not bother me in the least bit, I do Deep Air dives cause they are very easy for me and the most fun I get out of diving besides Spearing and collecting seafood.

This post reminds me of the saying......"Better to be quiet and thought of as a fool then to speak out loud and remove all doubt...." Just sayin...

 

[dumpsterDiver]

I've never agreed with the concept of 'acclimatization' to narcosis. I think that skills get ingrained - and ingrained stuff is less effected by narcosis. If something isn't ingrained, then it requires problem solving. Problem solving is effected by narcosis.

Diving beyond a reasonable narcosis threshold will always leave the diver at risk from unforeseen contingencies - if such contingencies fall beyond the ingrain response patterns they possess. As the diver gains more experience, those response patterns expand, but still won't cater for every eventuality.

It's the skills that decline. Acclimatization is a fairy tale.

Are you calling me a fairy? Because I will REPORT you, YES I will...

 

[DaleC]

Wow.....dude....all I can say is "clueless".....how about we jump out of a plane without a parachute....just to see if we can make it...? geez....

Your analogy doesn't equate. Jumping out of a plane without a chute is a 100% on/off risk. Diving deep on air is a graduated
risk involving several, interacting variables. While I may not personally agree that deep air is right for me I bet VDGM has more first hand experience with it's effects and implications than either you or I.

Well then my freind you have missed the point of most of these posts....I understood from the gist of these posts that >130 ft (WITHOUT THE PROPER EQUIPMENT AND TRAINING) = evil and death

Evil? Death? Let's not resort to hyperbole when the need does not exist. The case for and against can made on a much more rationale basis.

PS. How can someone be "new to diving" and "advanced" at the same time?

 

[VooDooGasMan]

Dopp I could agree in your statement that narcosis wins if your putting it as a competition or a game, and to win is to be able to control the narcosis. If narcosis wins you have a short time to clear it.

Devon has done narcosis game and I think is saying it is there for him like clockwork and knows his limitations of how buzzed and does not let narcosis win.

AOW student died in a very small student to instructor ratio, the young man died after paying an instructor to teach him deep diving, there needs not be anything about the actual dive to be able to consider the instructor can teach a diver to dive deep. When your talking recreational limits there should never be a death, unless the one teaching is not experienced enough, which is what has happen.


I am on board with dump on Acclimatization for my tolerance of narcosis.

 

[Kevrumbo]

Repost:

On adaptation to Deep Air and Nitrogen Narcosis:
"Moreover, our results suggest that experienced divers can discriminate between the behavioral and subjective components of narcosis. . .It has been proposed that the intensity of narcotic symptoms could be used by divers to gauge the extent of performance loss (10). The present results indicate that this advice is inappropriate for adapted divers because the two components of narcosis [behavioral and subjective] uncouple in a direction that could lead to an overestimation of performance capabilities --a potentially dangerous situation. On the other hand, the question arises as to whether adaptation confers any benefits on the diver, since performance efficiency is not directly improved and could be overestimated. In this regard, it could be argued that a reduction in symptom intensity reduces the possibility that attention will be focused on subjective sensations rather than the task at hand." [i.e. Subjective, sensations awareness vs. Situational, task-at-hand awareness??]
From:
p.9, Hamilton K, Laliberté MF, Fowler B. Dissociation of the behavioral and
subjective components of nitrogen narcosis and diver adaptation. Undersea Hyperb
Med. 1995 Mar;22(1):41-9. PubMed PMID: 7742709.