deep air

[dumpsterDiver]

.. there is no NEED to ever dive deep air or learn to manage narcosis.

There is no NEED to EVER do recreational/technical dives.

 

[LiteHedded]

There is no NEED to EVER do recreational/technical dives.

exactly.

 

[SurDo2]

OK, I've been biting my tongue this entire thread and some others that have come up regarding the subject of deep air or extended range diving. Deep air is fine, deep air is safe, deep air is done countless times every day the world over. There you have it. That being said the above statements are only true if the divers undertaking such dives have proper training, experience and equipment. Handling the effects of narcosis below 165 (or 130) takes a tremendous amount of experience, composure and skill. Also, the experience to call a dive when the diver gets that feeling that things "just aren't right" also comes into play. I'm sure there are those with limited diving experience who will say, "I've dove to 200 and I was fine". I'll say, "I'm sure you thought you were fine but in fact you were just lucky". I have extensive military and commercial dive experience but I am just now, 20 years into my dive career becoming interested in recreational diving. I am just getting underway with UTD and the whole DIR way of doing things. In fact, my first recreational dive setup is a DIR rig. I'm finding the whole process very interesting and fun. Coming from a military/commercial dive background were EVERYTHING is based on a team effort, uniformity of equipment, procedure and training is probably what attracted me to the DIR/UTD way of doing things. When I'm diving in a DIR setting I follow its rules, procedures, and training. Yes I bite my tongue sometimes but I joined them knowing how they do things. That being said I see and hear recreational divers talking about certain "truths" they hold dear as if it were gospel and berating those who don't agree with them. Now if someone like DCBC or Thassalmania wants to tell me their opinion on how I should plan and conduct a dive, I'll probably pay very close attention. If someone with only a basic OW or Tech cert wants to offer their advise I'll listen to what they have to say because they could have something to offer as well. Lately though, I've been meeting people who will refuse to dive with me or even talk diving with me because I dive deep air. As I said before, when I am diving in a technical team environment I play ball according to those rules. If myself and a guy I work with want to go check something out for fun on Sat morn at 200 that's my own business. But because I do this I'm considered reckless and dangerous no matter how I have conducted myself in the past underwater in a team environment. They want nothing to do with me because of my deep air diving outside of that setting. Bear in mind that I spend more time underwater each year than most people do watching TV and I have a tremendous amount of deep air experience. Don't get me wrong. Helitrox and Trimix and all mixed gases for that matter are great tools in the toolbox and I would love to dive them every day but they are not always available nor are they necessary from both a recreational and commercial/military/scientific standpoint.

 

[DCBC]

You know full well that there is a world of difference between the effects of narcosis at 50' compared to 200' for every diver.

Yes, but we are not making the case for every diver. We each dive individually and do so with varying levels of experience. It is up to each diver to dive within their own capabilities. It is not however up to anyone to suggest what those capabilities may be with further training and experience.

Where to draw the line for narcosis reasons is arbitrary - point taken. But, that doesn't mean that no line should be drawn.

I think that the only line to be drawn is that of safety. As you mention, this is arbitrary. What is safe for you, may not be safe for me, or vice-versa.

I'm not for a second arguing that you can't do air dive < 190' and come back alive again and again. I'm not arguing that you can't learn to manage narcosis. I have extremely little experience with either, and therefore would be a fool to make those statements. What I AM saying is that there is a better gas for these dives and there is no NEED to ever dive deep air or learn to manage narcosis.

Yes, there is always a better gas or multiple number of gases to be used. When using open-circuit however, we never get precisely the right gas in the same way as an eCCR, for example. We always use an imperfect gas, but it is within norms and acceptable for operation. What is "acceptable" is subject to interpretation to some degree.

As to your last sentence, "there is no NEED to ever dive deep air or learn to manage narcosis" is again dependent upon the divers needs. As Thal has mentioned, divers often dive in locations where air is there only option. This is not solely restricted to the scientific diving community and would suggest that recreational divers dive regularly in similar situations.

At 130' (the "sport diving" depth limit), some Advanced Divers are unsafe due to the effects of narcosis. They are certified to this depth, but can't take full advantage of it until they learn to manage this. We might not agree with it, but the fact remains that all divers diving below 50' are managing narcosis, to one degree or another.

Narcosis has been a killer of sport divers for many years. But we as Diving Instructors are NOT suppose to talk about its management??? This is what amazes me about Diving Instructors today. Their answer is go to another gas, take another course....

People will continue to dive air. Not all of them can afford or want to dive other gases. Why shouldn't we encourage them to learn to deal with narcosis so they can dive safely? I dare say that many members of this Board believe that if they dive to 100' that narcosis isn't even a factor. Perhaps because they haven't learned to identify it.

This is the real lie. It's not about bravado or seeking to take unnecessary risks. It's about teaching divers to dive their limitations and how to progressively increase them. I believe this is what continuing education is about.

It is that education and experience that prepares me to deal with underwater "situations" in a more competent manner, than I would have been able to, if I hadn't developed these skill-sets. This doesn't put me in a position to say that because of this I'm better than anyone. It is evidence however that I'm better than what I use to be. For me, that's reason enough.

I'm not about to do a dive on air past 250'. Why? It's not because someone has told me that I'm going to die; it's because at that depth I personally start to experience directional loss. I aborted the dive. That's my personal line-in-the-sand that I wont go beyond on open-circuit air. There are others on SB that dive air much deeper. For me this would be irresponsible.

 

[Thalassamania]

Harry Callahan: [about Briggs] A man's got to know his limitations.

 

[SurDo2]

I'm not about to do a dive on air past 250'. Why? It's not because someone has told me that I'm going to die; it's because at that depth I personally start to experience directional loss. I aborted the dive. That's my personal line-in-the-sand that I wont go beyond on open-circuit air. There are others on SB that dive air much deeper. For me this would be irresponsible.

That's about my limit as well.

 

[Dr Wu]

There is no NEED to EVER do recreational/technical dives.

There is no NEED to EVER dive anywhere. Ever.

 

[Tortuga68]

This board needs a 'No Thanks' button as well

 

[gcbryan]

I'm always amazed at the logic that says you don't need to experience something. You can personally choose not to experience something because of your own personally chosen limitations but it's just narrow-minded to choose the limitations for others.

It's especially narrow-minded to deny others the right to do something you haven't done yourself. If you haven't done it yourself then you really don't know what you're talking about.

Which usually brings up the lame statement that "I don't have to jump off a roof to know it's not a good idea".

If you never use air or never use air below 50 fsw then maybe you aren't the best source of whether it's possible to adapt to air and the ensuring narcosis at deeper depths.

If you've used air a couple of times at 130fsw and couldn't function maybe that's more about you than some universal truth. Actually do it more than a few times and your advice might be more meaningful.

Even so, what's the correct choice for one person isn't the correct choice for everyone else. One person may choose to dive deeper on air than another and yet choose not to penetrate caves or wrecks.

It's all risk management (which includes experience) to some degree and some seem not to get that.

Also, to ignore cost and logistics is to ignore the elephant in the room and it still leaves certain emergency situations where it could well be valuable to already know how you will react at deeper depths. To universally proclaim that you don't need this experience is just wrong on its face.

You may choose to rescue a buddy in trouble at a deeper depth. Sure, it's easy to repeat another cliche...don't compound the problem by adding a second body to recover but when you have to resort to cliches you usually don't have the benefit of a lot of thought on your side.

I do know and understand that divers have died this way trying to help a buddy. So what? Perhaps if they had more experience they wouldn't have died. Anecdotal evidence works both ways.

This absolute view on air and deeper diving seems to only have come to be not due to helium becoming more available but rather because of one or two agencies and their absolutist views on many things. It seems to me that 150 fsw is more the common recommended limit worldwide and that's not really a absolute limit.

Really, this is just a SB argument anyway. Those two agencies are highly represented on SB especially among the more active posters. Europeans dive deeper air every day and there doesn't seem to be quite the stigma that we see here it seems to me.

 

[Steve SDI/TDI HQ]

During a few years diving in a variety of conditions, and in particular the last 16 or 17 years diving and teaching technical diving, I have really only learned one thing. In the world of diving, there are few absolutes.

It seems that sensible dive planning and execution is the art of finding the correct balance between a number of conflicting issues. Each of these issues influences the likelihood of success through a highly complex network of physiological and psychological gears and pulleys that make the Enigma Machine look like a kid's toy.

I wish there were black and white answers; but there are not. At least not to the majority of questions. Argue all you want, the fog will not clear.

For example, we have become used to having the duration of the scrubber in a CCR measured in hours. Does that make sense? Of course it does not! Scrubber material works because of a chemical reaction. One of the outcomes of that reaction is that the material is spent... no longer does its job. If the quantity of scrubber material is a non-variable then the volume of carbon-dioxide that can be processed is non-variable. Time is not the issue... the number of litres of carbon dioxide pushed through the scrubber bed is the issue and that has little to do with time alone.

So it is with the deep air. The management of gas volume, narcosis, acute oxygen toxicity, ascent behavior, and the optimal operational depth of one's dive gear (all factors in planning deep dives regardless of the gases used) are challenges that cannot be met with anything approaching a definitive, this is black, this is white, answer no matter how hard one tries.



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