Deep diving advice that goes against conventional thought?

[teknitroxdiver]

So which agencies provide deep air training beyond 150FSW? PADI? IANTD? UTD? NAUI?

IANTD goes to 170. TDI does 180.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[Colliam7]

So which agencies provide deep air training beyond 150FSW? PADI? IANTD? UTD? NAUI?

PSAI does. Their 'Narcosis Management' training will ultimately take divers to 240' on air, as I understand it - PSAI Narcosis Management.

I went to 165' on air in PADI Tec Deep training.

 

[boulderjohn]

Therefore we will continue to have nitrogen diffusing into the blood stream no matter our breathing rate, as it is simply a pressure diffusion situation. The fallacy is that we can decrease this uptake of nitrogen by decreasing breathing. That probably is more a factor of heart rate than of breathing, as the blood moving through the lungs is where the gas exchange occurs. And this would be mostly independent of the inflation of the lungs.

This is correct, but it is very common for people to believe the opposite. Until you really think it through, it seems logical to believe that the amount we breathe in and out during a dive impacts the amount of gas we take on or give off from the body. There was a thread on SB a few years ago in which a very well known diver scoffed at people who had never been taught this supposed basic fact. As John says, your breathing rate has no effect on gas absorption in the tissues. That means everything the original statement says in relation to this is wrong.

In addition, not breathing in an attempt to avoid taking in nitrogen in the belief it will help with narcosis will probably make it worse. In doing so you will increase CO2, and CO2 is at least as narcotic as nitrogen, and probably more so.
------------------------

Now, about the "he's still alive" factor.

We sometimes forget that all of diving is to some degree a gamble. Even shallow dives bring a risk. The closest I have come to being in serious trouble came with a really bizarre entanglement after my buddy headed for shore at the end of the dive. I was temporarily but seriously stuck with my head about 2 feet from the surface. When we follow what almost all of us know as the normal limits of diving, the odds are very, very much in our favor. We have an almost guaranteed winning hand. As we begin to depart from what we think of as the limits of diving, we don't suddenly go to certain death. The odds just start going against us. The farther we get from normal diving limits, the worse our odds become. It does not mean we are going to die; it just means that survival is less certain.

That brings us to the concept now being called "the normalization of deviance." When you depart from standards in any activity and enter what was considered the margin of safety, the odds are that you will be OK. That is why it is considered the margin of safety. Do this a few times and you start thinking, "Huh. This works fine." It now becomes normal, and you do it regularly. Now you no longer have a margin of safety, and now the odds are not so overwhelmingly in your favor. That is when problems happen. (The term was invented to explain what happened in the Challenger disaster, when the space shuttle blew up after take off.)

---------- Post added March 12th, 2014 at 06:05 AM ----------

IANTD goes to 170. TDI does 180.

But this is starting to work its way out of the training. When I went through TDI training, the deep air part of the sequence (Extended Range) was not only optional, it was pretty much discouraged. I skipped it.

UTD, with whom I also trained, does not dive air or nitrox below 100 feet.

 

[ajduplessis]

IANTD goes to 170. TDI does 180.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

Nope! This from IANTD standards for deep air.

1. This Program is designed to provide responsible training to divers who plan to dive to a maximum of 130 fsw (39 msw) on air.

This from Program Limit section
"No dives may be conducted to depths greater than 130 fsw (39 msw)."

 

[teknitroxdiver]

Nope! This from IANTD standards for deep air.

1. This Program is designed to provide responsible training to divers who plan to dive to a maximum of 130 fsw (39 msw) on air.

This from Program Limit section
"No dives may be conducted to depths greater than 130 fsw (39 msw)."

Uh...yes! Deep Air is a recreational course. Look here: http://iantdcourses.com/nitroxdiver.php

"Technical Diver" is the program.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[boulderjohn]

Deep in the dim recesses of my memory I seem to remember an article in Sport Diver, maybe in 1996, written by Bret Gilliam (who I otherwise have a lot of respect for) detailing his 400 foot dive on air somewhere in the Bahamas following a DEMA or something. If the article, Bret told us how we shouldn't try this, but the way he did it was.... and then proceeded to outline many of the items in the OP's post. Minimal breaths to reduce nitrogen ongassing, shooting to the first stop from 4 bills + with no ascent rate limits, etc. When I read the article, I got mad, because I was afraid that some fool would also read it, and take it as a procedure to dive deep on air......

I did not read that article, but a few weeks ago I talked with him for a number of hours, and that conversation included a lot of his memories of those days. We have to remember that he and others of his time were true pioneers who paved the way to safe diving as we know it today. Many of our current best practices are the result of mistakes they made as they challenged the limits of diving. Unfortunately, some of the practices they followed that have since been abandoned and some of the mistaken beliefs they had then are still with portions of the dive community today. I think part of what he told me about his beliefs then and now about narcosis may be interesting in regard to this conversation because they show a difference between what they were doing on their deep dives then and what we encounter in our diving today.

What he is talking about in terms of narcosis at those depths is really pretty different from what we are talking about. He is not talking about a woozy feeling or feeling a little stupid or having a growing sense of fear. He is talking about being debilitated to the point of essentially passing out. He believed different people have different capacities in this regard, and the capacity is purely physiological. He talked about one of his frequent dive buddies in those days, a man he said was the most intellectually brilliant diver he ever met--the legendary Sheck Exley. Amazingly enough, he said this man, a record setter for scuba depth several times in his lifetime, had a poor capacity in terms of dealing with narcosis. He was unable to go to the same depths on air as the others on the dives that they did because of it. He feels that narcosis was the reason for Sheck's death. Even though he was on a very aggressive trimix ratio when he died, when you are below 800 feet, narcosis is still a factor. Sheck was curiously found tied to his descent line, and Brett believes that Sheck did that because he felt a debilitating narcosis hit coming and had tied himself off so that when he came out of it he would be able to continue with the dive. That seemed like a reasonable plan to him.

That is the kind of diving he is talking about, and it is probably not something most of us would want to emulate.

Gilliam's diving and his comments on it were not without controversy when he made them. He was strongly attacked by some other divers in his day, and he is still quite bitter about it. He sent me a collection he had assembled of vicious personal attacks from another famous name in scuba history. Wow! Were they harsh and personal! One was even a pretty clearly stated death threat. It would therefore be wrong to assume that what he wrote and believed then was the sense of the diving community, either then or now.

 

[PfcAJ]

incident free does not equal safe, and commercial diving does not equal recreational (as in 'for fun') diving.

When you've got a crew, a helmet, and coms, you can get away with a lot more.

 

[HIGHwing]

I went to 165' on air in PADI Tec Deep training.

And as a footnote the last dive of the course can be completed with normoxic trimix provided the student reads chapter one of the PADI Trimix Diver Book and the Instructor is suitably qualified with helium. PADI also has the Tec 45 Trimix and Tec 50 Trimix options for those who want Helium without posting 200' dives.

I get narc'ed pretty easily compared to many (or admit it earlier), so I just burn the gas I feel is most appropriate to me. All this deep air stuff is interesting, but a man has to respect his own limitations.

 

[danvolker]

I did not read that article, but a few weeks ago I talked with him for a number of hours, and that conversation included a lot of his memories of those days. We have to remember that he and others of his time were true pioneers who paved the way to safe diving as we know it today. Many of our current best practices are the result of mistakes they made as they challenged the limits of diving. Unfortunately, some of the practices they followed that have since been abandoned and some of the mistaken beliefs they had then are still with portions of the dive community today. I think part of what he told me about his beliefs then and now about narcosis may be interesting in regard to this conversation because they show a difference between what they were doing on their deep dives then and what we encounter in our diving today.

What he is talking about in terms of narcosis at those depths is really pretty different from what we are talking about. He is not talking about a woozy feeling or feeling a little stupid or having a growing sense of fear. He is talking about being debilitated to the point of essentially passing out. He believed different people have different capacities in this regard, and the capacity is purely physiological. He talked about one of his frequent dive buddies in those days, a man he said was the most intellectually brilliant diver he ever met--the legendary Sheck Exley. Amazingly enough, he said this man, a record setter for scuba depth several times in his lifetime, had a poor capacity in terms of dealing with narcosis. He was unable to go to the same depths on air as the others on the dives that they did because of it. He feels that narcosis was the reason for Sheck's death. Even though he was on a very aggressive trimix ratio when he died, when you are below 800 feet, narcosis is still a factor. Sheck was curiously found tied to his descent line, and Brett believes that Sheck did that because he felt a debilitating narcosis hit coming and had tied himself off so that when he came out of it he would be able to continue with the dive. That seemed like a reasonable plan to him.

That is the kind of diving he is talking about, and it is probably not something most of us would want to emulate.

Gilliam's diving and his comments on it were not without controversy when he made them. He was strongly attacked by some other divers in his day, and he is still quite bitter about it. He sent me a collection he had assembled of vicious personal attacks from another famous name in scuba history. Wow! Were they harsh and personal! One was even a pretty clearly stated death threat. It would therefore be wrong to assume that what he wrote and believed then was the sense of the diving community, either then or now.

I think it is worth noting, that George felt that the "peer group" represented by Bowden, Gilliam and others like them, romanticized the record setting and the adventure of these ridiculous deep dive record attempts.....and that such a "peer group" is what DID in fact cause Sheck's death ( by getting him to relax and break his own rules ) --and if you appreciate this perspective, then it is not hard to see how someone like George that was friends with a large number of the world's best exploration level divers at the time....would see the Gilliam and Bowden peer groups and members as people that he would see as murderers.....like a bartender that gets people falling down drunk, and then tells them they are fine to drive....Except this deep record peer group was worse, because they were GLORIFYING the driving drunk/deep attempts.

 

[Akimbo]

Yes, in-fact Table 6A (USN) requires that the Diver breathe 100% O2 for 25 minutes (then a 5m Air break before it's repeated) at a PPO2 of 2.8 ATA (approx 60 FSW)...

IMHO, Oxygen Toxicity is one of the more overstated and misunderstood diving maladies discussed on this board. Here is a link that explores your point in more detail:

Oxygen Toxicity Limits & Symptoms