Deep Air Diving - thoughts

[wedivebc]

In the academic world, before an article appears in a scholarly journal, it is first vetted by several academics in the field of good standing. This does not happen on SB. In this case, anybody with a computer can post as an "expert" and somewhere, somebody will take that person's advice to heart. There are tons of questions posted on this board that are answered by people with very little diving experience. Moreover, the bigger issue is that there is no way of knowing even whether you or I can actually "walk the walk" or are just "talking the talk". You are entitled to your view but mine is that it is next to ludicrous to take advice that can affect your survival in this type of circumstance. For items of next to little importance I might solicit opinions but for matters of potential life and death I will not trust the internet. I will instead meet people face to face and establish the bona fides before I take their advice. Just my 2 cents.

Fair enough but how does face time help? Bottom time maybe

 

[Bismark]

Fair enough but how does face time help? Bottom time maybe

Don't you do your deco face to face like any good DIR diver? Solves both problems at the same time............

In all seriousness though, I have a lot less trouble separating the wheat from the chaff when I meet someone versus seeing what they wrote on the internet. I'm guessing you were pretty picky about who you took your RB training from and didn't just sign up with someone based on advice provided on SB......... just my guess though

 

[LG Diver]

I've done a significant amount of work, on air, between 150 and 190 feet. That said, I should stress that I don't often dive in that range for fun or recreation. I am lucky that I don't often get particularly narced, when I feel that I am not doing well I immediately scrub the dive.

In my experience there are three keys to making deep air dives, the first is practice. I get in the pool or in shallow water and I perform the task that I will be doing over and over and over again. I do it with gloves on, I do it with my eyes closed, I do it with exactly the gear I will be using for the real thing, and then I do it again. The second is recognition that yesterday's immunity to narcosis may not mean jack today. The third is previsualization of the dive and the task. You need to take some quiet time on the deck, close your eyes and make the entire dive in your mind's eye. You need to imagine the things that can (and will) go wrong and think your way thought them, then rewind and pick up the dive where you left off.

Honest question- no agenda here. It sounds like you go through a lot of planning, preparation, and effort to get ready for a deep air dive. I'm curious why you don't, instead, put the planning and effort into doing that dive on mix and avoid the issue of narcosis altogether? Is it an unavailability of helium where you dive, or some other reason?

 

[peterbj7]

You don't build up tolerance

I disagree. The physiological effect is inescapable, but you can indeed reduce its effect on you by experience and conditioning. I would say that you are indeed building up tolerance.

I have rarely felt narced on any dive in recent years, and I have had my performance on deep air dives assessed by others (I'm not just relying on how I feel). But something people need to realise is that the practical effects of narcosis can be provoked and exacerbated by a relatively small but unexpected problem. You know, everything's going swimmingly at 180' on air and you feel great, then suddenly you feel breathing resistance. That can instantaneously convert your feeling of wellbeing into a chill down your spine, and that's accompanied by tunnel vision, developing panic and all the other classic symptoms. A VERY good reason for having deliberately stressful training where you have a serious life-threatening problem suddenly thrown at you, but when you have a mentor watching over you with the mental and physical ability to bail you out. The catalytic event for me was a LP hose bursting on an air dive at 190'. Another was a schrader valve on my CCR failing and injecting uncontrolled oxygen at around 300' on a mix dive. I feel that much scuba training these days is far too easy, and the first time anyone experiences a serious problem is for real when there's no-one around equipped to help.

A comment on mix. Helium can be frighteningly expensive even when it's available. Down here the buy-in cost for helium alone for a twinset dive to say 300' can easily exceed US$250. That's for a single dive! A powerful incentive to do those dives on a CCR.

 

[Kevrumbo]

From Shadow Divers:

. . . Kohler inhaled his trimix, the voodoo gas he had sworn would kill its heathen users . . . At 100 feet Kohler checked his mind for narcosis, and Chatterton checked Kohler checking himself . . . At 200 feet Kohler stopped on the anchor line to process the scene. On air at this depth, his vision would have already narrowed. "Unbelievable," he thought. "This is the difference between watching a portable kitchen TV and going to a movie theater. . ."

SOO, in summation of these posts concerning deep air dives:

1) you do not build a tolerance with successive dives

2) pre-visualization and familiarity with skills / equipment BEFORE the dive can really help

3) some days are worse than others narc wise

4) use trimix you idiot


That pretty much sum it up?

D>

Unfortunately, there are some places in the world where you cannot readily get helium --at the Blue Lagoon Dive Shop in Chuuk for example, they request at least a four-month lead time to guarantee a reserved shipment for your own exclusive use, for a premium cost of nearly $4.50/cf . . .:11:!

If all you have is Air for bottom mix 150'-180', and at least Eanx50 for deco along with the requisite training --enjoy yourself outside the wreck, take your time, compose & get some good wide angle photo shots. . .

 

[DA Aquamaster]

I disagree. The physiological effect is inescapable, but you can indeed reduce its effect on you by experience and conditioning. I would say that you are indeed building up tolerance.

Lets put the rest of my sentence back in play...

"You don't build up tolerance, but there is an improved effect on performance from work up dives. It is probably based on recency of experience and skills, familiarity under similar conditions, etc, but the effect is there."

When you post more than the first 5 words out of context and then read the rest of the post it becomes clear we both completely agree and are both talking about the same thing.

Its just an issue of semantics regarding the definition of "tolerance".

 

[Charlie99]

Diving deep air and getting narc'd is like learning to drink when you're a teenager. When you were 17, a couple of beers or wine coolers would probably drop you on your a$$ - similarly, your first dive down to 150 feet could do the same.

With time, and experience, repetitive dives teach you how to operate in that type of environment, I would even go so far as to say that your body begins to tolerate that type of stupor, and you learn to perform better at deeper depths with successive dives.

I think that the better analogy is that as a new driver at 16 or 17, you have a couple beers and are way over your head when trying to dRive. After 10+ years of practice driving, you still get just as drunk, but now your driving is more automatic and the apparent effect of a couple beers is less. In reality, you're just as drunk.

IMO, the same sort of thing applies to narcosis and diving. With experience and practice, you can handle normal routine stuff while narc'd, but you have less ability to handle emergencies or other abnormal situations.

 

[DA Aquamaster]

In the academic world, before an article appears in a scholarly journal, it is first vetted by several academics in the field of good standing. This does not happen on SB. In this case, anybody with a computer can post as an "expert" and somewhere, somebody will take that person's advice to heart. There are tons of questions posted on this board that are answered by people with very little diving experience. Moreover, the bigger issue is that there is no way of knowing even whether you or I can actually "walk the walk" or are just "talking the talk". You are entitled to your view but mine is that it is next to ludicrous to take advice that can affect your survival in this type of circumstance. For items of next to little importance I might solicit opinions but for matters of potential life and death I will not trust the internet. I will instead meet people face to face and establish the bona fides before I take their advice. Just my 2 cents.

I agree with you completely. But after spending 3 long yars in higher education teaching and directing programs, I cannot begine to describe the politics surrounding publication or the perils and pitfalls of attempting to publish research that goes against the established grain.

Higher ed is not an environment of enlightened and open minded individuals but more often an enviroment of turf wars, oversize egos and petty infighting where ideas remain mainstream until the dinosaurs who built thier careers promoting those ideas, right wrong or otherwise, finally have the courtesy to retire or die. Similarly, those seeking advanced degrees are often forced into an existing mold as radical ideas that upset or challenge the established order will not get the student promoting them a Ph.D.

So I agree there is value in the vetting process, but some of the best research ever done, if it gets published at all, will never get published until long after the opposition promoting older ideas fades away.

 

[DA Aquamaster]

I think that the better analogy is that as a new driver at 16 or 17, you have a couple beers and are way over your head when trying to dRive. After 10+ years of practice driving, you still get just as drunk, but now your driving is more automatic and the apparent effect of a couple beers is less. In reality, you're just as drunk.

IMO, the same sort of thing applies to narcosis and diving. With experience and practice, you can handle normal routine stuff while narc'd, but you have less ability to handle emergencies or other abnormal situations.

That's a good analogy, except alcohol use does involve tolerance as your synapses respond to elevated levels of alcohol over time by increasing the production of neuro trasmitters and or receptors to restore normal function in a chemically depressed environment. That is why alcoholcs display tremors when they are sober - an excess of neuro transmitters and related signals.

When I was in college in my young and stupid days, a 12 pack was a warm up for the weekend and driving after 5 or 6 beers was not a problem. Now, 20 years later when I drink maybe one beer a month, and a BAC chart states I can drink 5 beers in 1 hour and be under the legal limit of .8 based on my weight and gender, the reality is that I would have problems finding the parking lot, let alone my car. Good Lord, I shudder to think of the consequences that would result if I actually drove!

A man's got to know his limitations - and that definitely applies to deep air diving.

 

[Bismark]

I agree with you completely. But after spending 3 long yars in higher education teaching and directing programs, I cannot begine to describe the politics surrounding publication or the perils and pitfalls of attempting to publish research that goes against the established grain.

Higher ed is not an environment of enlightened and open minded individuals but more often an enviroment of turf wars, oversize egos and petty infighting where ideas remain mainstream until the dinosaurs who built thier careers promoting those ideas, right wrong or otherwise, finally have the courtesy to retire or die. Similarly, those seeking advanced degrees are often forced into an existing mold as radical ideas that upset or challenge the established order will not get the student promoting them a Ph.D.

So I agree there is value in the vetting process, but some of the best research ever done, if it gets published at all, will never get published until long after the opposition promoting older ideas fades away.

Been there done that. I agree whole heartedly. Now when can we expect this to happen to the "deep air" school?