My Journey into UTD Ratio Deco

[rjack321]

I assume by this that you are publicly accusing me of lying.

Here is a thread I started in March of 2011 in which I talked about it.

Differences in Ratio Deco

In that thread I mention a conversation I had via PM with Jarrod Jablonski of GUE on that topic. Jarrod said that a GUE diver should not use RD at altitude because it was not devised for altitude diving. I have preserved that conversation but will not print it unless Jarrod were to agree to that.

I was still a UTD member than, although that ended pretty quickly after that. I was threatened by UTD because of the thread. I was told that if I started a thread like that again, I would be reported to PADI for violating their standard against disparaging another agency, and I could be expelled. That pretty much finished off our relationship.

I know you aren't lying. We have never met but I have enough history with RD to know that the opinion that "altitude doesn't matter" was widespread for many years. Roughly until folks in CO started getting bent pretty bad. I will point out that the CO UTD instructor at the time seemed to have some pretty wild ideas in general and is no longer with the agency.

ps I am happy to see my tune about the stops being too deep has not changed in 7yrs I have continued to try and push the first stop upwards however.

 

[boulderjohn]

I will point out that the CO UTD instructor at the time seemed to have some pretty wild ideas in general and is no longer with the agency.

My information came directly from Andrew. We argued about it via email. He said he knew it didn't matter because he dived at Lake Tahoe without making any adjustments, and he felt fine.

He also said no one had ever been bent at altitude using RD. In the argument about the thread I started, I was told that the people who got bent using RD at altitude did not count because there was some reason other than altitude for their being bent, and we knew that in all such cases there had to be a different reason, because RD could be used at altitude without adjustment.

 

[rjack321]

My information came directly from Andrew. We argued about it via email. He said he knew it didn't matter because he dived at Lake Tahoe without making any adjustments, and he felt fine.

He also said no one had ever been bent at altitude using RD. In the argument about the thread I started, I was told that the people who got bent using RD at altitude did not count because there was some reason other than altitude for their being bent, and we knew that in all such cases there had to be a different reason, because RD could be used at altitude without adjustment.

Yes I remember that asinine circular logic... Although I cant believe it was 7 yrs ago.

 

[mikeny9]

I assume by this that you are publicly accusing me of lying

You are projecting. I never called you a liar.

However, any time UTD Ratio Deco is remotely mentioned on this board you always seem to want to derail the discussion into your personal experience with Andrew Georgitsis and how he told you, apparently, that it works fine in altitude diving. However, altitude diving is and always has been outside the UTD Ratio Deco course. We've heard this from numerous students of the course and UTD instructors on these boards. I've personally spoken to the other IT who designed the course. Let's be 100% clear, as @CAPTAIN SINBAD mentioned, altitude diving is outside the scope of UTD Ratio Deco.

A more likely story is you misinterpreted what Andrew was saying, took it out of context, or both, and always use that as a device to discredit him, UTD, or UTD's Ratio Deco course. This hints at some sort of agenda or ulterior motive. Why were your instructors/friends expelled from the agency?

 

[boulderjohn]

I see--in saying you are not calling me a liar, you are calling me a liar. Please note the post where I linked to a 7-year old thread when I was still a UTD member and talking about Ratio Deco and altitude.

 

[mikeny9]

You can read into that as much as you'd like, I'm illustrating how there are two sides to this story.

 

[nadwidny]

You are projecting. I never called you a liar.

However, any time UTD Ratio Deco is remotely mentioned on this board you always seem to want to derail the discussion into your personal experience with Andrew Georgitsis and how he told you, apparently, that it works fine in altitude diving.

Back just before AG was unceremoniously forced from GUE he taught us about RD and we were told altitude doesn't matter. And O2 % as well. So it's not just one guy that was told that.

UTD may have changed that but there is still the fact that at one time it was part of AG's repertoire.

 

[CAPTAIN SINBAD]

Back just before AG was unceremoniously forced from GUE he taught us about RD and we were told altitude doesn't matter. And O2 % as well. So it's not just one guy that was told that.

UTD may have changed that but there is still the fact that at one time it was part of AG's repertoire.

It was part of GUE repertoire too. Here is a direct conversation with George Irving:

Audience: A question I wanted to get to but it's getting a bit late now: we have Lake Tahoe here at 6000ft. How would you deal with diving at that altitude?

George: I basically ignore it. [audience laughs] You can calculate altitude in the programs and all. Your body adjusts right away anyway just so it all becomes relative again. Stay at Lake Tahoe for a couple days, your body is at 6000ft and stays there. So it's not going to be like you're going beyond decompression steps when you get out of the water. It not you could be beamed to Lake Tahoe and do a dive and come up. But I pretty much ignore that altitude silliness. They make too much of it, I think. But I went skiing at Lake Tahoe, and didn't have any problems. [audience laughs] I didn't get bent. But I really don't know. I mean, I don't know of anybody that ever had any issues with any of that. But they always have some special deco. But I've never seen any problems. I really don't know, though. It's out of my realm, other than I don't believe it. From what I know of decompression I don't believe it's a problem. That's got to be a cool place, though, to dive.

BAUE George Irvine Lecture

 

[CAPTAIN SINBAD]

On a second note, the higher GF lows that are now coming back in after NEDU study are similar to the profiles that were getting people bent prior to the NEDU study. Here is a quote from George Irvine:

"Going back to depth, what we found was if we didn't do deep stops we got skin bends. And the other thing we got bent in odd tissues that would then later swell and cut off circulation. You'd get paresthesias in the extremities. You'd wake up at 2:00 in the morning sweating and your arm is numb. That kind of stuff. And the way we were able to figure it out was by diving odd profiles like where a cave would come up rapidly and there would be a lot of overhead clearance like a bell shaped room. In other caves there was an entrance where the cavern had a lot of overhead clearance above the floor depth. We get sloppy and start switching bottles and moving around and then next thing you know you thought you're at 180 and you're at 100ft. So you say "What the hell, I'll just drop, grab my 120 bottle". That's where we're getting these hits. What I call hits — nothing was happening right away. You didn't feel that bad, but you would get these problems later like skin bends and paresthesias and other odd symptoms. So we figured it had to be from bubbles that were trapped in tissues at depth that weren't being eliminated later. And generally hours later these bubbles will grow bigger as they pull more gas into themselves. Four or five hours after the dive, they'd will reach maximum size before they dissipate in the tissues. They pull other gas into themselves and get bigger. That would be enough to cut off circulation or squeeze a nerve or pressure something to cause that feeling of numbness. You didn't have a brain hit — that would have been instantaneous. Right away. So it's not a central nervous system hit, it's a central nervous system result. It ends up being same as, as far as the symptoms without the overt damage.

So we started experimenting on where to stop and we determined that 80% of the profile is the correct starting point. So if it is a ten atmosphere dive, 80% of the profile is eight atmospheres — 240ft roughly — for your first stop from the 300ft dive. So we started implementing that." (George Irvine)

BAUE George Irvine Lecture

I would love to hear how modern science explains these skin bends. Is George Irvine lying? Is he telling the truth but he is a biological oddity? I find it a bit odd that Richard Pyle did most of his dives in Hawaii and never met George Irvine. yet both of them were reporting getting bent on shallow stops and these bends would mysteriously vanish when deep stops were added.

Thoughts?

 

[Kevrumbo]

And with regard to the NEDU Study, they (JJ, AG, GI3) were all mistaken about the original efficiency of Deepstops in RD as well:

Quoting Jarrod Jablonski in the linked article below:
". . .The earliest technical diving uses of deep stops were based almost solely upon personal experience. Several individuals, many within our group, toyed excessively with various ranges of deep stops, employing progressively deeper stops for varying times and then shortening the times in the pursuit of maximum efficiency. George Irvine and I pushed these and other assumptions to their limits, consistently striving to develop a means of maximizing decompression efficiency; George has been especially aggressive in this regard, helping to establish a true minimum range for decompression times. Divers from the WKPP established several working rules of thumb for deep stops, such as the convention of a first stop that should start one atmosphere shallower than one's maximum depth during the dive . . . Here, deep stops are specifically defined by the point in which ambient pressure and leading compartment pressure (theoretical pressure within body tissues) are equal. Deeper than this point would actually result in on-gassing, while too shallow could promote bubble formation. . ."

See also Decompression Experimentation | Global Underwater Explorers