Deep Diving on Air

[boulderjohn]

I am not sure peter how that goes, yet I do believe a lot of it is the money.

I did a number of dives last year with people who did deep air dives because they did not want to pay for helium. It appeared to be fairly common in the area of South Florida in which I was diving.

On the other hand, not a single one of them was doing the single tank bounce dives being described here. Every one of them was using well accepted technical diving protocols. They all had plenty of gas with them. They had redundancy. They had made careful dive plans with decompression profiles plotted out. They all used high nitrox percentages for accelerated decompression.

Not wanting to pay for nitrox on a planned 150 foot dive is not a reason to throw all other safety factors away, too.

 

[dumpsterDiver]

The incident was reported HERE. As I said, no change to the dive plan.

I still don't see what this has to do with planning a dive which is deliberately on thin margins for gas and requires perfect execution to be completely safely, at a depth where perfect execution might be expected to be a difficult goal to attain.

Maybe I'm seriously biased because we lost a young man here in Puget Sound, a couple of years after I got certified. He did a deep bounce dive on an Al80 on air, with the encouragement of a man he respected, who had been an instructor. He didn't get into trouble, but his buddy did -- narced out of his mind and crawling in the sand. The diver in question saved his buddy, and ran out of gas on ascent. His body wasn't found for about a year. The parallels between this and Opal's death are just too close for comfort. I really, really hate to see anyone die diving.

It was not the size of the tank (thin margins of gas) that caused the death in 200 feet. It sounds like it was simply excessive narcosis. The buddies didn't stay together well enough (possibly narcosis) and another guy totally gets narced out. They probably had planned an executable dive, but the narcosis prevented execution. It sounds like more air may not have prevented a guy from crawling around on the bottom.

Which brings me back to my main point, it is primarily the narcosis which is so dangerous for deep air dives, not the bends or running out of air. Planning to take enough air is easy, taking deco gas is easy, but the narcosis "variable" is the wild card... and that is exactly why 150 isn't 200 and 200 isn't like 250 and hell i don't know what 300 is like.

 

[Rhone Man]

the narcosis "variable" is the wild card... and that is exactly why 150 isn't 200 and 200 isn't like 250 and hell i don't know what 300 is like.

That is the solid truth. And it doesn't help that it varies so wildly from diver to diver. Lynne gets uncomfortable below 90 feet. I am pretty comfortable within myself to about 150 feet or so, but by 180 feet I am not really stable. Experienced deep air divers like John Chatterton and Gary Gentile were comfortable doing complex penetrations at up to 240 feet on air. And Brett Gilliam was able to do maths puzzles at nearly 500 feet on air. Unfortunately for some, finding out their limitations was the last thing that they did in this world.

 

[Rhone Man]

There is a lot of butt-hurting on both sides surrounding this issue. It is seriously getting us nowhere. Stop the chimpanzee-esk poo-flinging and just let it die.

I take it that this is your first deep air thread on SB?

 

[PfcAJ]

The problem with 'comfort' is that you're perceiving your own comfort while under the effect of the narcosis. Its the same thing as when a drunk person says 'I'm fine to drive'. Orly?

That is the solid truth. And it doesn't help that it varies so wildly from diver to diver. Lynne gets uncomfortable below 90 feet. I am pretty comfortable within myself to about 150 feet or so, but by 180 feet I am not really stable. Experienced deep air divers like John Chatterton and Gary Gentile were comfortable doing complex penetrations at up to 240 feet on air. And Brett Gilliam was able to do maths puzzles at nearly 500 feet on air. Unfortunately for some, finding out their limitations was the last thing that they did in this world.

 

[Bob DBF]

Which brings me back to my main point, it is primarily the narcosis which is so dangerous for deep air dives, not the bends or running out of air. Planning to take enough air is easy, taking deco gas is easy, but the narcosis "variable" is the wild card... and that is exactly why 150 isn't 200 and 200 isn't like 250 and hell i don't know what 300 is like.

That is the solid truth. And it doesn't help that it varies so wildly from diver to diver. Lynne gets uncomfortable below 90 feet. I am pretty comfortable within myself to about 150 feet or so, but by 180 feet I am not really stable. Experienced deep air divers like John Chatterton and Gary Gentile were comfortable doing complex penetrations at up to 240 feet on air. And Brett Gilliam was able to do maths puzzles at nearly 500 feet on air. Unfortunately for some, finding out their limitations was the last thing that they did in this world.

And that is the crux of the Bounce Dive problem, A diver who has spent most of his time in the 0 to 100' range makes a dive to 200' without knowing his tolerance to narcosis, and how to deal with the issue, thinking that it is a minor player in the dive. Winds up they are dead wrong.

It isn't the fall that kills you, it's the sudden stop at the bottom.



Bob
--------------------------------------
I may be old, but I’m not dead yet.

 

[DaleC]

I don't recall Lynne calling me a bad diver. We may sometimes disagree on certain points but I always get the sense that she is sincere and thoughtful in her responses and not guided by the need to ridicule or stick it to someone.

Sometimes to stop a trainwreck one needs to stop feeding the troll but sometimes a poster just has a unique style that makes them seem like a troll. I can see it clearly in this thread and I bet others can as well. Continuing to poke sticks in an attempt to incite an entertaining reaction that reenforces the superiority of the clic gains far less respect than the inevitable reaction in my books.

As far as narcossis goes; while I think predicting or preventing when it will occur can't be done I do believe that experience with it aids in coping with the effects. The first few times I experienced dark narcs I believed the symptoms were reality, that there was really something to be anxious about. With more experience I began to recognize that this was just a symptom and I could employ certain things to cope with it. Mostly this is mental redirection and/or recognizing that I need to wrap up what I'm doing and head up in the water column (but in a calm fashion). If I completely avoided narcossis I would not have gained this experience and would be caught off guard when it did occur.
I don't really get happy narcs though (that I know of ) and this is probably another reason why I don't go deeper than I do.

And, I haven't had a drinky drink in 28 years - I bet many daily drinkers could handle a couple of stiff ones way better than me.

 

[Rhone Man]

The problem with 'comfort' is that you're perceiving your own comfort while under the effect of the narcosis. Its the same thing as when a drunk person says 'I'm fine to drive'. Orly?

Sure, that's the old argument. I define 'comfort' as being aware of my own limitations (ie. knowing that I am too drunk to drive). When you lose comfort (in my opinion) is when you cease to have sufficient wherewithal to be aware of your own limited capacities.

I have had stark illustrations of how my mental capacity becomes sharply more limited at 120 feet. I am still OK with going deeper than that, but I am very aware that I am not playing with a full deck.

 

[MXGratefulDiver]

It was not the size of the tank (thin margins of gas) that caused the death in 200 feet. It sounds like it was simply excessive narcosis. The buddies didn't stay together well enough (possibly narcosis) and another guy totally gets narced out. They probably had planned an executable dive, but the narcosis prevented execution. It sounds like more air may not have prevented a guy from crawling around on the bottom.

Well, since the guy who died was a friend of mine ... and I still dive with one of the guys who survived that night ... I'll give you the crib notes version of what happened.

Instructor dude wants to do a 200-foot bounce dive. Convinces his DM-candidate (my friend) to come along. Then he gets a really NEAT idea ... why not combine this with his ongoing AOW class. He'll have them do their deep dive and night dive all in one ... a quick bounce to 200 feet off a clay wall in Commencement Bay. There are three AOW students, two with less than 15 dives total, and another friend.

Instructor dude buddies up with one student. DM candidate with the friend. And the final two AOW students are buddies. It's dark, windy, and recent rains had put enough runoff into the water to put visibility between 3 and 5 feet down to about 30 fsw, where you could get below the halocline.

The three buddy teams swim out to the wall ... about a 15-minute surface swim ... in chop and darkness. Keep in mind that two of these were very new divers. They start the dive. Before they clear the halocline, the two AOW students who were buddied together get separated and bail ... they never made it below 30 feet. They surface swim back to shore. The other two teams descend down past the wall, hitting bottom at about 205 and immediately begin their ascent. Four went down, three are coming up. DM candidate looks down, sees a light, and goes back down. Sitting on the bottom is AOW # 3 ... too stupid to move. DM candidate grabs him and starts hauling him back up. Probably due to exertion, DM candidate runs out of air at about 160. His final act was to reach out and inflate AOW #3's BCD, rocketing him to the surface from 160 feet. Dm candidate then drifted off into oblivion. That was the last anyone saw of him until 10 months later, when another friend of mine found him half-buried in the mud at just over 200 feet. AOW #3 spent the rest of the night in the chamber at St. Joseph's. Instructor dude was permanently banned from NAUI.

Believe it or not, that's the short version ... as a footnote, the guy who found the body had a narcosis-induced accident of his own a few months ago and is still on the mend. I truly hope he's able to fully recover and dive again.

... Bob (Grateful Diver)

 

[DaleC]

That is a very sad story Bob. I had a similar (though not a deep bounce related) "trust me" incident early on that had three of us hoping desperately and helplessly for #4 to surface from near zero vis. until the CG hovercraft arrived. Fortunately for us all ended well.