UTD Ratio deco discussion

[Diver0001]

Is it so very different than when calculators came out and those that had built their understanding around the use of a slide rule insisted that learning the slide rule was important to understanding how numbers work? That didn't last very long as I recall.

I decided that learning tables was important while my wife called bs on tables and paper log books from the moment she heard about them. She is also the one that pushed for getting the Perdix. People see things differently. Finding the similarities and learning to use them to form a basis for cooperation and team building matters far more than who is right. BTW, I don't think that just because we hide the algorithm inside a magic box on our wrist makes it immune to being based on incomplete and potentially faulty reasoning.

Especially in regards to subjects that are not completely understood, the need to believe that someone knows so that we can hang our hat on their understanding is not "scientific". It is closer to religion.

Question:

How many (as a percentage) of dives do you make on the tables?

How many (as a percentage) of dives does your wife make using a computer?

I would put money on knowing the answer. Namely, "almost zero" in your case and "almost 100" in her case.

This is why, as an instructor, I feel that preparing students to dive with computers.... namely, the tool they are going to use in real life.... is important!

I also feel that it is important to help students understand deco theory, which I can do very well without using the tables as an example. In fact, I would seriously and sincerely suggest that my OW students understand the latest thinking in deco theory better than AG. This isn't intended to be a jab.... it's based upon what he says, what the experts say and what my OW are taught. I honestly and truly think that my OW students "get it" and that AG is stuck in a paradigm lock.

Again, I don't want that to sound like a jab... but I honestly believe that AG is stuck in a paradigm lock and I honestly believe that my OW students could teach him a thing or two.....and that they actually understand the basics better than he does.

R..

 

[RainPilot]

All RAID courses after OW must be done on computers.

On OW there is a choice of tables IF the student after CONSIDERABLE encouragement has decided they don't want to buy/rent a PDC.

 

[RayfromTX]

Question:

How many (as a percentage) of dives do you make on the tables?

How many (as a percentage) of dives does your wife make using a computer?

I would put money on knowing the answer. Namely, "almost zero" in your case and "almost 100" in her case.

This is why, as an instructor, I feel that preparing students to dive with computers.... namely, the tool they are going to use in real life.... is important!

I also feel that it is important to help students understand deco theory, which I can do very well without using the tables as an example. In fact, I would seriously and sincerely suggest that my OW students understand the latest thinking in deco theory better than AG. This isn't intended to be a jab.... it's based upon what he says, what the experts say and what my OW are taught. I honestly and truly think that my OW students "get it" and that AG is stuck in a paradigm lock.

Again, I don't want that to sound like a jab... but I honestly believe that AG is stuck in a paradigm lock and I honestly believe that my OW students could teach him a thing or two.....and that they actually understand the basics better than he does.

R..

We never have and never will dive tables. I don't use my slide rule either. Learning tables was not a waste of time for me. I didn't learn them because I thought I would ever dive them. I have a question for you. Did you get the impression from what I wrote that I dive tables or ever thought that it would be a good idea to do so? I only said I thought it was a good idea to learn them. Not to do so puts one at a disadvantage in understanding the history of diving at the very least.

If you want to get the point across to those that believe in emphasizing deep stops that it is problematic, then insulting their agency or the man that represents what they have been basing their safety on is not likely to put them in the open frame of mind that would be required for them to hear you. People have pride in their knowledge and have invested time in acquiring it. Telling them that they just don't get it is counterproductive. When they start to consider another approach, it is best if we don't talk down to them. The goal should be to keep them in the conversation which requires that they feel respected. This following post may not have accomplished that.

I'm glad to hear this, Mike and I think that gives an opening.

Once again I wasn't trying to be rude to you and I have no bone to pick with you personally. Hell, we don't even know each other.

People almost always need to experience some kind of cognitive dissonance in order to shake them out of an "unaware" state in order for learning to be (re)started. In cases where people are really stuck in a paradigm lock making them feel that cognitive dissonance isn't easy and it isn't comfortable. I wasn't trying to play "king of the castle" with you, I was sincerely making an attempt to help you reach a mental state in which learning could (re)commence in the best way I could think to do on an internet forum.

In part this approach was also to break through the exchange of stand points from the trenches we were getting in this thread without any real progress being made in understanding.

I don't know if the result vindicates the approach but the fact that you said above that you are willing to listen is a BIG step further than you were 5 days ago or so when you joined this thread.

What I would recommend now is for you to listen very carefully to what John is saying. I'll also try to help you understand the significance of the NEDU study you have heard about in the context of RD if you are willing to be patient. There are also other NEDU studies to consider that you might not yet know about. I don't recall if any tested ratio deco specifically (I don't think so) because it's really a niche thing, but the conclusions of several top deco scientists, when you project it on to what you THINK you know about deco theory, will change how you think about this entire topic. I think in the end you'll be much better off if you can get to a point of thoroughly understanding what the research really means.

You have 10 years of catching up to do so please try to be patient as the discussion progresses from this point. A good starting point is to review the NEDU study that you have heard about again. It's all about deep stops, not the O2 window, but the ascent strategy involved in RD makes use of deep stops.

If you were to suspend "belief" for a moment as "assume" that NEDU is right then the obvious conclusion from the deep stops study is that deep stops are not "good" at all in the sense of it making deco more efficient. On the contrary, the addition of deep stops means that MORE time, not less time, needs to be spent shallow in order to compensate for an ascent strategy that keeps you deeper longer. On an intuitive level this might make some sense, but NEDU proved it.

If you are anything like me, the first time you read that study you're going to have a lot of questions. The research was specifically designed to highlight differences between different ascent strategies but they made dives on gasses and deco schedules that no technical diver would do in the real world. It took me reading that study multiple times and reading extensive discussions about it on the internet, including with the people who designed the study, for me to understand that the science really is solid and that conclusion really is relevant. At first I thought it designed to get a certain result, in other words, starting from a conclusion and working back to an experiment that reached that conclusion. That might be your impression too, but it's not the case.

So let's just start with that.

R..

 

[Diver0001]

If you want to get the point across to those that believe in emphasizing deep stops that it is problematic, then insulting their agency or the man that represents what they have been basing their safety on is not likely to put them in the open frame of mind that would be required for them to hear you. People have pride in their knowledge and have invested time in acquiring it. Telling them that they just don't get it is counterproductive. When they start to consider another approach, it is best if we don't talk down to them. The goal should be to keep them in the conversation which requires that they feel respected. This following post may not have accomplished that.

Fair enough. So I'm not the one to get them to see the light. I can't help but call a spade a spade....

I'm sorry but I do believe that their leader is paradigm locked and I do believe that my OW students have a better understanding of the issues in modern deco theory than he does. That's my job......to teach them. His job is to push his agenda. I'm not just saying this. I believe it.

So where does that leave us?

I'm not anti UTD or anti any "alphabet soup". Hell, I teach for an agency that gets more flack --by FAR -- for quality than any other. I'm PRO skills and I'm pro knowledge. UTD have some outstanding divers. I know this. One of my favorite ever people on this planet and probably my favorite dive buddy ever was a hard-core UTD diver. Pro skills and pro knowledge. It used to be what DIR was about.

It was what DIR was about 15-odd years ago. It purported to be the best practice in diving. Bill Main invented the config although he would distance himself from that now, George Irvine's personality, as abrasive as it was, and "abrasive" is putting it very mildly, reduced deaths at WKPP and AG figured out how to train divers in the system.

All of that was hardening the paradigm in stone. There was ONE way to do things. Anyone who disagreed was wrong and dissension was akin to heresy. AG learned that and took it to UTD when he started that. He made it into a cult of personality and the cult of personality defines where UTD is today.

R..

 

[mikeny9]

I don't know if the result vindicates the approach but the fact that you said above that you are willing to listen is a BIG step further than you were 5 days ago or so when you joined this thread.

I was and am willing to listen always, my position hasn't changed. I'm not sure how you thought I wasn't but I think you probably made a few presumptions about me that are incorrect. You presumed I hadn’t read the NEDU deep stop study when I had.

You claim there are are elements within RD that have been “debunked.” I’ve asked you three times now which elements, to which I’ve gotten no reply. Honestly, I don’t think you really understand much about RD and are relying upon incomplete or false information to draw conclusions about it.

There are also other NEDU studies to consider that you might not yet know about.

Which?

I don't recall if any tested ratio deco specifically (I don't think so) because it's really a niche thing

They haven't.

People almost always need to experience some kind of cognitive dissonance in order to shake them out of an "unaware" state in order for learning to be (re)started. In cases where people are really stuck in a paradigm lock making them feel that cognitive dissonance isn't easy and it isn't comfortable. I wasn't trying to play "king of the castle" with you, I was sincerely making an attempt to help you reach a mental state in which learning could (re)commence in the best way I could think to do on an internet forum.

Is this a patronizing and passive way of you telling me I need to experience “cognitive dissonance?” What other studies and facts can you show me to aid me in such cognitive dissonance?

You have 10 years of catching up to do so please try to be patient as the discussion progresses from this point. A good starting point is to review the NEDU study that you have heard about again. It's all about deep stops, not the O2 window, but the ascent strategy involved in RD makes use of deep stops.

I know it’s about deep stops, not the O2 window, which is why I mentioned that specifically. The ascent strategy involved in RD makes use of 66% deep stops, and doesn’t use air for decompression. Comparing the two is not a like-kind comparison.

If you were to suspend "belief" for a moment as "assume" that NEDU is right then the obvious conclusion from the deep stops study is that deep stops are not "good" at all in the sense of it making deco more efficient. On the contrary, the addition of deep stops means that MORE time, not less time, needs to be spent shallow in order to compensate for an ascent strategy that keeps you deeper longer. On an intuitive level this might make some sense, but NEDU proved it.

You’re taking the deep stop study out of context. It involves using only air for decompression. I will agree with you that if we are using air only then adding deep stops adds more time, not less time, to the overall ascent.

If you are anything like me, the first time you read that study you're going to have a lot of questions.

If I was anything like you, I’d be more presumptuous and patronizing

However, the going "paradigm" is that "deep stops" allow for shorter shallow stops later. THIS idea needs to go. It is wrong and NEDU proved it.

I don't believe any theory in RD subscribes to that idea. Do you know how RD works?

In fact, I would seriously and sincerely suggest that my OW students understand the latest thinking in deco theory better than AG. This isn't intended to be a jab.... it's based upon what he says, what the experts say and what my OW are taught. I honestly and truly think that my OW students "get it" and that AG is stuck in a paradigm lock.

Again, I don't want that to sound like a jab... but I honestly believe that AG is stuck in a paradigm lock and I honestly believe that my OW students could teach him a thing or two.....and that they actually understand the basics better than he does.

R..

But this is a jab. If you say, “this isn’t a jab,” but then make a jab, it’s still a jab lol . First of all, in order to make that statement, you must already know how much AG knows about deco theory. Is that true? Are you claiming you know how much AG knows about decompression?

I'm sorry but I do believe that their leader is paradigm locked and I do believe that my OW students have a better understanding of the issues in modern deco theory than he does. That's my job......to teach them. His job is to push his agenda. I'm not just saying this. I believe it.

What paradigm lock are you referring to? Ratio deco itself? Do you know how RD works? Have you taken a class? You were the one telling me to “go read, then talk.” I don’t think you understand at all how RD works. Your job is to teach, his job is to push an agenda? Are you sure you’re not pushing an agenda too?

So, what kind of training is offered so that the diver can make an "informed decision"? What is the source of this information?
...
At what point in the training are they taught how to make those informed decisions?

I would hope that someone would know what UTD officially teaches. So far, no one knows.

For the 8th/9th time, UTD doesn't teach anything about altitude diving in RD. I'll keep going I guess, how many can we get to, 20 times?

So let’s go with the 9th time? UTD doesn’t officially teach anything about altitude diving.

 

[Patoux01]

You’re taking the deep stop study out of context. It involves using only air for decompression. I will agree with you that if we are using air only then adding deep stops adds more time, not less time, to the overall ascent.

And yet, many people, more knowledgeable than you and I, have considered this a large novelty. And completely reflecting reality of using other gases.
Do you believe that because you switch to a gas with less inert gas, your previous gas load will be slower? How do you reconcile the "because they didn't use O2 for deco" with "by adding deep stops when I'm on my back gas I reduce the amount of deco" ?


Btw, there's also another study (about VPM) that revealed high bubble levels in divers after a "normal" dive.

 

[Diver0001]

Sorry Mike. I actually thought you were ready to listen.

My bad. It's ok though. I don't really care to save everyone.

R..

 

[PfcAJ]

You claim there are are elements within RD that have been “debunked.” I’ve asked you three times now which elements, to which I’ve gotten no reply.

Do you have any evidence that extending stops at a po2 of 1.6 increases decompression efficiency?

I know it’s about deep stops, not the O2 window, which is why I mentioned that specifically. The ascent strategy involved in RD makes use of 66% deep stops, and doesn’t use air for decompression. Comparing the two is not a like-kind comparison.


You’re taking the deep stop study out of context. It involves using only air for decompression. I will agree with you that if we are using air only then adding deep stops adds more time, not less time, to the overall ascent.

Do you have any evidence that deep stops (using any gas) reduce shallow stops? The NEDU study suggests that deep stops do not increase decompression efficiency. Any evidence to the contrary?

 

[mikeny9]

And yet, many people, more knowledgeable than you and I, have considered this a large novelty. And completely reflecting reality of using other gases.
Do you believe that because you switch to a gas with less inert gas, your previous gas load will be slower? How do you reconcile the "because they didn't use O2 for deco" with "by adding deep stops when I'm on my back gas I reduce the amount of deco" ?

Btw, there's also another study (about VPM) that revealed high bubble levels in divers after a "normal" dive.

Right, there’s always bubbles present after any dive. It’s the size of the bubble that counts. The deep stops added in RD 2.0 is meant to control the size of those bubbles, not accelerate deco time. O2-based decompression would certainly accelerate the ascent when compared to air.

Sorry Mike. I actually thought you were ready to listen.
My bad. It's ok though. I don't really care to save everyone.
R..

Hmm, I've been listening all this time. I've asked you questions, and you're not answering them. What more can I do to listen @Diver0001? Just because I don't agree with you doesn't mean I'm not listening. Could you start with answering my questions?

Do you have any evidence that deep stops (using any gas) reduce shallow stops? The NEDU study suggests that deep stops do not increase decompression efficiency. Any evidence to the contrary?

AJ, nope. Like I wrote above, RD doesn’t aim to reduce any of the shallow stop time specifically by adding deep stops. I don’t think it ever did. The idea with the deep stops in RD 2.0 is simply to control the size of the bubble growth, not the presence of them. It in no way reduces your shallow stop time, as that time is necessary to treat the slow tissues.

RD 2.0 calls for adding 1 min deep stops when exceeding NDL by 15-29 minutes. Based off the NEDU deep stop study, then additional time should be added to the shallow stops to treat slow tissue super-saturation. I would certainly agree with that, but the study also doesn’t factor in oxygen-based decompression. UTD RD 2.0 doesn’t call for 66% stops until you’re 15-29 minutes over NDL, in which case the diver would certainly be using either 50/00 or 100% O2.

 

[Patoux01]

Right, there’s always bubbles present after any dive. It’s the size of the bubble that counts. The deep stops added in RD 2.0 is meant to control the size of those bubbles, not accelerate deco time. O2-based decompression would certainly accelerate the ascent when compared to air.

Wow. Please, I really mean this for your own good. Grab a book like deco for divers and do some reading.

VGE is considered an indicator of deco stress. Deco stress is what you're trying to minimize.


Edit: Oh, and also, don't take deco courses from Ross, because that's dangerous.