Deep Air

[LiteHedded]

With regards to the Rouses, their Last Dive was made on air but it was 1993 and roughly half the other divers on the boat were diving air as well. Although the use of air undoubtedly contributed to the serious nature of their situation on the bottom, it was not what killed them.

After everything on the bottom had gone bad, they did a free ascent off the wreck, and miraculously located the anchor line at about 100 feet. They had a way back to the boat, they had gas to breath, and with one minor exception their gear was working well. Chrissy's mouthpiece, on their one deco bottle, apparently had a small hole in it and he was getting water with every breath.

With everything that had happened, being entrapped in the wreck, getting lost, having to make the decision for a free ascent, and now having an issue with the regulator, Chrissy had enough and chose sunshine and seagulls, from 100 feet. Chris followed his son.

They had everything they needed to survive with them, except the resolve to stay in the water and complete their decompression, or at least some part of it. For their indiscretions, sadly they had to pay the price.

Resolve and determination, not air.



Regards

JC

why isn't that enough? should we not stack the odds in our favor so that small issues don't snowball into larger ones?

 

[DCBC]

Do you think the previous generation of deep air divers would have become deep air divers if helium, proper training and tools like Vplanner had been as readily available to them as they are to us?

Great question!

I'm sure yesterday's diver could be enticed to do this, but because something can be done, doesn't necessarily mean it should be. Another question might be: What is lost by quickly moving to mixed-gas to perform relatively shallow dives?

Prior to mixed-gas recreational diving, divers became more acclimatized to recognizing and dealing with the affects of narcosis. Deep air dives were for experienced divers only. The new diver dove to ever increasing depths over a long period of time, preparing themselves for the day where they would be competent to be included in such a dive.

Commercial divers then and now regularly use air as the primary gas for most diving operations less than 200'. Helium has been available in the commercial field for ages, by is not used unless it's needed. Divers are expected to have the experience necessary to dive safely on air to a depth of 175', although it is used deeper in some circumstances (my maximum is 250').

I'm sure my father secretly shook his head at me when I first started to go to school. I use to complain about the long bus ride, where in his time, he had to walk 3 miles across open prairie to get to school; a long way for a five year old in the winter. To him, I was privileged. It would do me good not to have things so easy. I didn't understand this until I was much older.

It's the same today. People in our Society want instant gratification. Technology is allowed to make up for many of our short-comings. If you give some young people a mathematical problem and hand them a piece of paper and a pencil, they can only answer it if they have a calculator. No calculator, no answer. I hope the world never runs out of batteries...

Diver's are prepared to dive as long as the technology is there. If it's not, or something goes wrong, they're over their heads. Sometimes too deep for their experience.

Can they do a 200' dive? Sure, where's the Trimix? No trimix? No dive.... I'm happy to use mixed-gas as well, but if it's not there, I'll do it safely on air; that's what's being lost.

Personally, I believe in mastering one gas before moving on to another. But I'm sure this would be considered an antiquated viewpoint by many people on SB.

With proper experience, most people can dive relatively deep on air safely. For those of you who use Trimix, no problem. Others may choose to develop their ability to use deep air. Where this really bears fruit is when a Trimix diver finds himself without the gas and has to fall back on their often limited deep air experience, or forgo the dive.

 

[Thalassamania]

The point, at least as I see it, is that mixed gas is nothing new, it goes back to the thirties, I was first exposed to it in the mid 1970s during NOAA's use of the Helgoland Saturation Habitat for the Herring and Hydroacoustics Project. Rec-Mix divers today like to pretend (or perhaps they are taught) that they have discovered something new, the fail to recognize that its been there a long time. Mix is a tool, deep air is a tool, its nice to have both in your basket. But it is rebreather technology (at least from the perspective a diving scientist working at remote sites) that really makes the difference and that makes mix practical.

DCBC's point about being a capable and experienced deep air diver before moving to mix is, I think, a good one.

 

[HowardE]

I e-mailed this to a friend, and he asked me to post this response:

I was forwarded the dialogue about deep air diving and let me make a few comments on the subject. Firstly, 99% of the divers out there have absolutely no business diving deeper than about 190 fsw on air due to potential issues with both narcosis and oxygen toxicity, not to mention properly handling the decompression and contingencies that might arise.

Secondly, my original book (Deep Diving: An Advanced Guide to Physiology, Procedures & Systems) was written in 1991 to help offset the incredible lack of practical information on the subject. I went to great pains to detail the tragedies that had resulted from ill-planned record attempts and to put the physics and physiology topics into plain language for average people to read and understand. I later did a massive update on the book increasing its size by over 150 pages and updating it in 1995. It remains in print today and has sold over a 100,000 copies in several languages. If you want a signed copy, send your check for $30 to me at: Bret Gilliam, 54 Stonetree Rd. , Arrowsic, ME 04530. I'll have it out the next day. It's still the best single resource on the subject.

Thirdly, both O2 tox and narcosis are highly subjective in their effects on an individual. Many of us who came from military/commercial/scientific diving backgrounds found that our tolerance was dramatically improved by frequent deep diving and a thusly acquired "adaptation" that has been clinically proven. Tom Mount, Sheck Exley, Jim Bowden, Joe Odom, and myself had incredible tolerances for narcosis. Part of this was based on experience and the huge amounts of diving in such environments that we did routinely. But another big factor was our in-depth understanding of the subjects and not being afraid of the exposures. Fear is a huge detriment to performance... But it is also a valuable inherent trait that serves to protect people from doing things they should not. And, as I said before, 99% of divers simply should stay shallower and avoid the risks. Some divers who were extraordinary performers in challenging situations like cave penetrations, wreck work, or high risk filming with sharks, etc. did not have tolerances for narcosis. It was just not something that was apart of their genetic make-up. Most of them learned quickly to avoid extreme depths. One example was British cave diver and Blue Hole explorer Rob Palmer. Rob, a dear friend, was one of the best divers I've ever known but had a very low tolerance for narcosis. Sadly, he was killed in 1997 on a deep dive in the Red Sea. It was not planned to be excessively deep but the divers were accidentally dropped in blue water with no bottom or drop-off wall reference. Many of us suspect that Palmer's death was, at least, partly due to narcosis and what is known as "deep water blackout".

Fourthly, the era in which deep air diving was practiced by the small cadre of professionals who could do it was not so much about records. Indeed, the fact that some of us achieved record depths was incidental to our work or exploration. But the primary reason we used air was because helium was either not available in remote areas or was so expensive then as to be impractical for a lot of our applications. If we could get the job done on air, we had no problems with that. But we did not advocate it for others and went out of our way to point out the hazards to try to prevent others from killing themselves.

Finally, when I broke the long-standing record of Watson & Gruner in 1990 by going to 452 fsw, I beat their mark by over 25 feet. I was not unduly impaired and actually stayed at depth to complete a series of mental tests for cognitive function before making my ascent without incident. In contrast, both Watson & Gruner were completely out of it (by their own admission), had no memory of getting to their maximum depth at all, and were lucky to have survived. Every diver that attempted to break their record later died in the process until my success 25 years later. Subsequently, another whole squad of divers killed themselves trying to break my record (my deepest was in 1993 to 475 fsw). When Dan Manion tried to set the record, he got to depth but, once again, was totally incapacitated by narcosis and barely survived.

In closing, deep air diving was a practice that existed out of necessity before other tools such as mixed gas became cost-efficient and more widely available. Also, using open circuit for deep dives is also now out of date since rebreathers are far more efficient. The key to survival is knowing all you can about the subject, a body of experience, and the confidence earned by repetitive work in such environments. It's also crucial to adapt and employ the technological advances that evolve and use the best equipment systems to get the job done. There is nothing "safe" about deep diving no matter what systems you employ. But you can mitigate the hazards by using the tools available wisely. Otherwise, you're just going to end up as another lesson in Darwinism.

Be smart. Dive wisely. Be informed and educated. And don't exceed your personal limits. I'm sure everyone has more to live for than trying to simply set a record that is now meaningless anyway. If you need to see your name in a record book, there is always the New York hot dog eating contest every year. The worst that can happen there is puking and indigestion. And I like hot dogs!

Bret Gilliam
President, OCEAN TECH

 

[Thalassamania]

While Bret and my views as to what constitutes "Deep Air" are quite different, I agree with the concept of what he is saying. I'd also like to point out that 190 FSW has been the limit for air diving for the science community for almost 60 years and we have never had a accident or decompression incident of any sort in the range of 130 to 190 FSW.

 

[walke121]

the rouses. I remember those guys. They did dive air didn't they? what was it that happened to them again? I forget.

That was a little uncalled for. You don't have to be such a.. never mind. Litehedded you are so closed minded it crazy. If people don't do things the way you were taught apparently they are wrong. It is impossible to have a simple debate with you. You do realize that you are sitting here arguing with people that probably have more deep dives on air than you have dives. No one is saying that helium isn't a wonderful gas but apparently you feel that if you dive deeper than 100fsw on air you are an idiot which isn't the case. Have you really gone back and read some of your posts? You must be the world's foremost expert on diving. I haven't seen anyone on this board so set in their ways.

 

[DCBC]

I'd like to echo Thal's remarks. There is deep and there is insanely deep. In all due respect to Bret Gilliam, 475' on air is insane! I'm sorry, but someone who dives like this just isn't in a position to lecture anyone on diving safety. He has no credibility. I'm aware of his outstanding record and respect him for it, but I have a hard time with: Do what I say, not what I do.....

Over the past 37 years, I've been a professional diver with the Navy and a commercial diver. I dive deep saturation for a living. I know my limitations and don't push myself into the complete unknown.

This was not always the case, as I was the Diving Operations Officer (Navy) at DCIEM, where I largely acted as a Guinea Pig for several years. I didn't think that this was overly extreme as the dives were within the World's most advanced recompression facility (wet and dry) and I was under the constant scrutiny & attention of many leading hyperbaric physicians.

475' on air? Just not very smart!

 

[ucfdiver]

but apparently you feel that if you dive deeper than 100fsw on air you are an idiot which isn't the case.

I'm not so sure about that, I've done it, and I fell well within the complete idiot category in doing so. Even worse, you begin to surround yourself with more idiots who convince you it's safe, convince you adjust to it, and use a series of uneventful dives (which most dives are) to "prove" how safe it is. Those of us that cave dive could dive halves a few 100 times, and chances are we'd never experience a gear failure, and it would prove "safe" to dive that way....but none of us plan our dives like that.

You must be the world's foremost expert on diving. I haven't seen anyone on this board so set in their ways.

Quite the compliment for litehedded, seeing as all he's done is look at deaths and learn from them, even many of my non diving friends know how dangerous diving intoxicated is, and they couldn't even tell you how to use a dive table. We've had 2 technical diving deaths aided by unacceptable END's within the past month, it doesn't take a very experienced diver to analyze that and tell you that's not a good idea.

 

[Trace Malinowski]

I've added thanks to many posts here, not because I necessarily agree with the use of deep air, but I believe that history is important to understanding and much of diving history is being lost. Also, there are divers with a lot of deep air and gas experience who really know what they are talking about with regard to gases being employed for commercial and scientific purposes. It's refreshing to read a deep air Internet discussion that is mostly moving along as a mature and informative thread.

 

[DCBC]

I've added thanks to many posts here, not because I necessarily agree with the use of deep air, but I believe that history is important to understanding and much of diving history is being lost. Also, there are divers with a lot of deep air and gas experience who really know what they are talking about with regard to gases being employed for commercial and scientific purposes. It's refreshing to read a deep air Internet discussion that is mostly moving along as a mature and informative thread.

Trace, You have a lot of experience and are well traveled. If trimix/heliox is not available, what limits do you personally place on air? Is there a line you will not cross? How do you deal with this issue?