TDI Extended Range - last words of advice?

[brockbr]

I gotta applaud that clear and concise example of common sense (not always as common as I'd like). I always try do the right thing in the right situation and not force the square peg through the round hole.

Deep air? No thanks. Do the dive that your gas choices/equipment/experience/training/teammates/environment/etc. safely permit.

Just my two cents...Cheers!

Ok - I'll admit - I've done air to 216' on CCR. I've done many 180' dives on air on CCR too - A few of those were on the USS Oriskany inside the ship itself. If you think for one second that I'd risk my life to do those dives, you're wrong - Period. How do I empirically know I wasn't screwing up and was well in control of my faculties? Let me think... There is enough silt and hazards around to tattle on bad trim or buoyancy.

JC's comments are 100% on the mark. Learning about deep air is a natural progression to learning more dangerous tools.

By the way, try doing air at 200' on CCR, and you will QUICKLY find out why the smaller molecule of He is so critical - Pulmonary collapse is more frequently being reported by divers who are on an air dil at deeper depths. I've done exactly 2 dives on CCR on air below 200', and I wouldn't recommend it to anyone

I am just a noob CCR/MOD3 (advanced trimix) + CCR/full cave diver, but more importantly I know when to listen to the older, wiser divers like JC.

 

[TSandM]

I suppose this isn't really legitimate here, because it didn't happen to me, but I did hear this story from the person to whom it happened.

My Fundies instructor, who does not dive deep air, was talked into doing a wreck charter dive in Croatia. The wreck was at something like 120 feet, and he was reluctant, but he went. When they reached the wreck, he heard bubbles from somewhere behind him. He reached back and closed his left post, but the bubbles persisted. He isolated and thumbed the dive, about five minutes into it. As they ascended and stopped, he thought he would reach back and do a flow check, and he found that his left post was OPEN. He had gotten confused and either turned the valve the wrong way, or turned it partially closed and then opened it. Either way, a man who teaches this stuff and does valve drills in his sleep had gotten confused on air at 120 feet and turned a valve the wrong way, costing him the expensive charter dive.

His point was that you really don't know how impaired you are, until you have to respond to something out of the ordinary, and even then, you may not realize how poorly you have reacted until you get shallow enough to think.

I think we can all make risk-benefit decisions with respect to our diving -- we all have to. Based on my own experiences with narcosis, and stories like this one, I'll keep my END to 100 feet. I won't condemn someone else for doing something different, although I may shake my head and wonder why, but I hope everybody else will give me the space to make that decision for myself and the safety of my teammates, and not condemn my decision, either. (Shake your head at it if you want )

 

[DA Aquamaster]

While I don't think its the reg that is much a limiting factor as bronchioles feel free to stack the deck against yourselves, to save money, acclimatize to the buzz, whatever else you use to justify cutting corners. The good thing is you ain't diving with me.

Debating something with you is a lot like trying to squish the air (or in your case helium) in a balloon. You squeeze one end and the bulge pops out somewhere else. In effect, if one argument that you promote is questioned, you just slide right out from under it and move on to another.

Now you just decide to use your own rationalization and dogma to try to discredit any opposing argument by calling them rationalizations. There is a real logical fallacy for you. You'd think helium would clear up that kind of thinking even at 1 ATM.

 

[rjack321]

Debating something with you is a lot like trying to squish the air (or in your case helium) in a balloon. You squeeze one end and the bulge pops out somewhere else. In effect, if one argument that you promote is questioned, you just slide right out from under it and move on to another.

Now you just decide to use your own rationalization and dogma to try to discredit any opposing argument by calling them rationalizations. There is a real logical fallacy for you. You'd think helium would clear up that kind of thinking even at 1 ATM.

Lovely. How many times do people have to point out to you that one little tidbit in isolation is not particularly critical? A 0.79 fraction of N2 is not horrendous, until you account for the additive or possibly synergistic effects of CO2, which is on top of a little extra WOB, which is on top of the added decompression stress. The sum is that air doesn't do anything well except maybe save money.

 

[battles2a5]

Why do you think that is? Because the DENSITY of air is too much work! Continue to think that gas density is irrelevant if you wish. But even a fit diver can be overwhelmed by high currents and excess work, just like even a marathon runner can burn out on a steep enough hill. There's no good reason to put the odds against you by choosing gear or gases that are known to be more difficult. Are you still using a bleach bottle BC?

Ugh... this is exhausting. You are citing extreme medical cases in a completely different context from what we are dicussing. You are talking about people who lack the physical ability to breathe comfortably on their own with the CO2 production of 2 gases with marginal differences in density. You guys have this black and white view of the world where this is only one answer to any situation. The rest of us are pragmatic. As I stated earlier, in warm, clear, calm water the situation is much different than in a challenging environment. Narcosis, CO2, physical endurance, etc. etc. etc. all have personal limitations. Most of us believe that the thresholds for thest things vary by environment. You obviously aren't going to push those limites in a high flow system or a cold, dark, deep, dive but in other situations its not as much of a factor. You obviously do not, although I still would like to hear about what experience you and Bismark have with deep air that have led you to form these beliefs. Preach all you want, but most people are still going to do it. And most people see absolutely nothing wrong with it.

As I said before, good luck w/ the class Rhone Man. My apologies for the hijack.

 

[Bismark]

Ugh... this is exhausting. You are citing extreme medical cases in a completely different context from what we are dicussing. You are talking about people who lack the physical ability to breathe comfortably on their own with the CO2 production of 2 gases with marginal differences in density. You guys have this black and white view of the world where this is only one answer to any situation. The rest of us are pragmatic. As I stated earlier, in warm, clear, calm water the situation is much different than in a challenging environment. Narcosis, CO2, physical endurance, etc. etc. etc. all have personal limitations. Most of us believe that the thresholds for thest things vary by environment. You obviously aren't going to push those limites in a high flow system or a cold, dark, deep, dive but in other situations its not as much of a factor. You obviously do not, although I still would like to hear about what experience you and Bismark have with deep air that have led you to form these beliefs. Preach all you want, but most people are still going to do it. And most people see absolutely nothing wrong with it.

As I said before, good luck w/ the class Rhone Man. My apologies for the hijack.

Preach? I really don't care how you want to dive, or how anyone else does, unless they are diving with me. I do care when people of little experience like yourself would rather support their own views rather than look at the science. But heh, I don't know you and you don't know me so I can only guess you are speaking from your plethora of experience. You were 4 years old when I was certified.

 

[Dtaine]

JC's comments are 100% on the mark. Learning about deep air is a natural progression to learning more dangerous tools.

Why shouldn't you learn about it, through the research and experiences of those before you, and make the choice not to dive it and get trained with He mixes instead?

Let's take one of JC's analogies a step further:

Trimix is a powerful tool, for use by craftsmen. Before you can utilize it properly and to its potential, you need to become a craftsman? Would you give a 4 year old a circular saw? You can't just show him the buttons and tell him to be careful?

If trimix is a circular saw, then I guess you could say air is a handsaw. If I'm training somebody to do a job that is easier and more efficient with a circular saw, then should I force them to do that job with a handsaw 2, 3, 4 times or more before progressing to the circular saw? Why bother, just train people to use the right tools for the job first.

To the OP - best of luck with your training.

 

[Kern]

What a waste of time...............

What an obfuscation.......

You guy's have already wasted a lot of time in this thread hijack, so why not answer the question.

Come on, a simple yes I have or no I haven't, is all it takes.

Have fun on the course RM.

PS. you will be narced.

 

[Bismark]

What an obfuscation.......

You guy's have already wasted a lot of time in this thread hijack, so why not answer the question.

Come on, a simple yes I have or no I haven't, is all it takes.

Have fun on the course RM.

PS. you will be narced.

You would be be better served to read all the post in the thread. I don't know how to make my posts come out in crayon. Must be a system glitch.

 

[Bismark]

If trimix is a circular saw, then I guess you could say air is a handsaw. If I'm training somebody to do a job that is easier and more efficient with a circular saw, then should I force them to do that job with a handsaw 2, 3, 4 times or more before progressing to the circular saw? Why bother, just train people to use the right tools for the job first.

To the OP - best of luck with your training.

So why is it that you can figure this out with very little experience but someone with hundreds or even thousands of dives can't? That is the part I could never figure out.

To the OP, I also wish you the best of luck with your training.

I'm out of here.