Slow tissue on gas from stops

[atdotde]

Where is this function, please?

You have to turn it on with a checkbox (compute plan variations), then it’s printed next to the total runtime.

 

[Dan_P]

I've seen some of the online UTD videos. This cult seems very impersonal to me.

I got that
It's the use of the word "cult" that'll make a chap feel shoehorned a tad. It's my opinion that I "often" see assumptions about how the diving/training is carried out paint a wrongful picture and subsequently quite strong reactions.
Depending on venue, UTD is also occasionally known as a "longhose cult", "frog kick cult", "neutral bouyancy cult" - it's often less about whether, in the eye of the beholder, the choices are agreed with, than whether the choices are understood.

This misrepresents the scientific picture. All the scientific information we have says that deep stops add risk to profiles. One study specifically studied UTD-RD and, although it was granted 44% more stop time, the profile generated higher decompression stresses than a GF30/85 profile without the additional time. As such, we can conclude that the UTD-RD profile tested was at least 44% inefficient by the study's test criteria.

Current research would support the idea that UTD-RD is more dangerous, and less safe than readily available alternatives that don't emphasize deep stops. In my view it IS irresponsible to downplay this research and the potential that it could be indicating levels of risk unknown to us due to lack of study that a diver might not want to assume if known.

We can keep going at this one all day long, but instead, let me just say my opinion is that calling RD "dangerous", "unsafe" or "irresponsible" with basis in science, is misrepresentative.
If one cannot or will not deviate from an algorithmic perception, one could call the RD framework "suboptimal" and other takes on that word - that'd be more fair game, but still omits several relevant points;
Recall that UTD does not force instructors/divers to use RD, that if they choose to do so, they are encouraged to adapt it, and that UTD is clear that it's not a scientific formula.

 

[tursiops]

We can keep going at this one all day long, but instead, let me just say my opinion is that calling RD "dangerous", "unsafe" or "irresponsible" with basis in science, is misrepresentative.
If one cannot or will not deviate from an algorithmic perception, one could call the RD framework "suboptimal" and other takes on that word - that'd be more fair game, but still omits several relevant points;
Recall that UTD does not force instructors/divers to use RD, that if they choose to do so, they are encouraged to adapt it, and that UTD is clear that it's not a scientific formula.

My previous post was removed because someone thought it was a personal attack. I'll try again. The quote above is BS. Articulate, Yes, but still BS.

 

[Blasto]

1) "UTD forces people to use Ratio Deco"
Absolutely not. UTD offers Ratio Deco, but instructors/divers can choose whichever option they prefer.
2) "Ratio Deco is a written in stone"
We have seen from UTDs procedures that it is not written in stone, but in fact is very open to personal adaptation.

So, In short...

RD is an impractical deco strategy, known to be inferior to both modern and old computers. But it's still good, because UTD doesn't require you to use it the way they teach it, or at all.

 

[Dan_P]

So, In short...

RD is an impractical deco strategy, known to be inferior to both modern and old computers. But it's still good, because UTD doesn't require you to use it the way they teach it, or at all.

You find it "impractical" - okay, you have every right to feel that way. But why do you feel that way, if you don't mind me asking?
You can say the doctrinary framework is suboptimal to some algorithms in terms of the physiological decompression process, sure, but "impractical" and "...inferior to both modern and old computers" makes me genuinely curious.

 

[Blasto]

You find it "impractical" - okay, you have every right to feel that way. But why do you feel that way, if you don't mind me asking?

It imposes higher task loading, increases the chance of mistakes, and reduces decompression efficiency compared to the alternative (dual ZHL computers + memorized Subsurface deco plan).

You can say the doctrinary framework is suboptimal to some algorithms in terms of the physiological decompression process, sure, but "impractical" and "...inferior to both modern and old computers" makes me genuinely curious.

Being less optimal is a way of being inferior. And it's almost every tec computer that is better (closer to optimal).

 

[Dan_P]

It imposes higher task loading, increases the chance of mistakes, and reduces decompression efficiency compared to the alternative (dual ZHL computers + memorized Subsurface deco plan).

I think we should disambiguate here;
a) the principle of using some standard deco paradigm
b) the level of deep stop emphasis applied

The reason I think it makes sense to make that disambiguation in our discussion, is because separating those two will make it easier for us both to understand what the other means.

I believe, correct me if I'm wrong, what you're refering to from the two above, is a) the principle of using some standard deco paradigm.
Yes, a "standard" deco will always be physiologically suboptimal to "optimal" deco, no matter what the deep stop emphasis is going to be. It's as the names imply. The reason one would use such a "standard" solution, is because one finds it practical regardless.

We have seen examples of why one would feel that way, previously in this thread - including from divers who don't otherwise defend RD.

It is my understanding that the reason you find it impractical is - I'll paraphase you here so let me know if you're not satisfied with my representation - "it imposes higher task loading and thus increases the risk of mistakes".

I would offer the following thought on your view on task loading:

What if it doesn't increase the task loading, but more precisely, it imposes an increased training requirement.
It means that you must be a better, more experienced, diver to carry out the same dive. It highlights to you that you're uncomfortable performing a simple mental task while doing the diving you're doing.

Would that make you consider that maybe overrelying on a computer is not a problem just because the computer can fail, but rather because so many other things can go wrong and that would also increase the requirement on a diver to think?

I've seen literally tonnes of divers who were formidable case studies of mentally "surviving" in their diving, and it was masked by a computer. Those divers would seriously benefit from at the very least training with RD, because it would bring to light that the limiting factor for them was their situational awareness and mental surplus.
The problem is not that their computer may fail. Their limitation was that just about anything going seriously wrong, would push them beyond their capacity.

I'm not saying that divers who opt for computers are bad divers, don't get me wrong on that.
But do you see what I mean when I say that RD has significant training utility?

Being less optimal is a way of being inferior. And it's almost every tec computer that is better (closer to optimal).

That would depend on which algorithm you put into it. And even so, that's only one perspective - the physiological decompression perspective. We still can't disregard apects such as practicality.

 

[Blasto]

I would offer the following thought on your view on task loading:
What if it doesn't increase the task loading, but more precisely, it imposes an increased training requirement.
It means that you must be a better, more experienced, diver to carry out the same dive. It highlights to you that you're uncomfortable performing a simple mental task while doing the diving you're doing.
Would that make you consider that maybe overrelying on a computer is not a problem just because the computer can fail, but rather because so many other things can go wrong and that would also increase the requirement on a diver to think?[
I've seen literally tonnes of divers who were formidable case studies of mentally "surviving" in their diving, and it was masked by a computer.

I see your point.

But the same increase in mental effort can be achieved by playing chess or writing blog posts on a slate while diving. It also stresses and tests one's mental ability, but without introducing any risk of confusion in their deco protocols.

The chance of both computers failing, plus the dive also changing so much as to invalidate the pre-dive deco plan is quite negligible. To the extent that there's no more utility in practicing calculating a deco protocol that isn't the one you plan to use than in practicing something else.

 

[UWSojourner]

We can keep going at this one all day long, but instead, let me just say my opinion is that calling RD "dangerous", "unsafe" or "irresponsible" with basis in science, is misrepresentative.

I know your knack for closely parsing language, that's why I was careful to say ...

Current research would support the idea that UTD-RD is more dangerous, and less safe than readily available alternatives that don't emphasize deep stops.

 

[Dan_P]

I see your point.

But the same increase in mental effort can be achieved by playing chess or writing blog posts on a slate while diving. It also stresses and tests one's mental ability, but without introducing any risk of confusion in their deco protocols.

The chance of both computers failing, plus the dive also changing so much as to invalidate the pre-dive deco plan is quite negligible. To the extent that there's no more utility in practicing calculating a deco protocol that isn't the one you plan to use than in practicing something else.

I get your point, and would add only that chess and writing has little utility in-water. I could also use soduko to practice boyancy, but Basic-6 (and Basic-5 and similar) do the same job - practice bouyancy - while offering an applicable utility.
So does "standardized deco", but I think that many do not understand how.
However, I think we've seen a few good examples, even from people who by no means are advocates of RD or UTD.

I think that we'd do well to remember which risks there are in relation to confusion - remember, you'd also have a pre-dive plan, and you'd still need to knock out a whole team of "computers" (brains) in either case.

My point is, the risk, as I see it, is in diving beyond limits. When diving beyond limits, awareness is out the window.
My view is that if diving within limits, "standardized deco" is at least as "confusion proof" as having a number of computers - particularly if they're all using the same software, but that's beside the point.

The "standard deco" paradigm allows me to very easily test the students' awareness (I'll refrain from elaboration), develop it, and it gives me a pretty good indication that I'm getting beyond my limits if I have a hard time dividing a number by 3, or multiplying a number by 2, on the "3-times-table".
That gives you a rough idea of the complexity level.

Besides, I already have a plan. The key here is, even when in-water, I think "what else could I do with what I have?", and if I land on something attractive, I can adjust to that. But my initial plan is in place until I have a new plan in place - if I fail to make such an adaptaion and agree on it with one or two other autonomous brains, the original plan stands and/or I'm calling the dive.

I know your knack for closely parsing language, that's why I was careful to say ...

Current research would support the idea that UTD-RD is more dangerous, and less safe than readily available alternatives that don't emphasize deep stops.

Okay, I'm not going to argue with that.

But, let's also agree that with the logic that the above means RD would be irresponsible, "all divers are strokes" would work for a non-diver. It's about accepting a risk for a benefit, I think.