Dan, I know only one of the divers I referred to as being associated with John's group.
No correlations like extreme altitude, taught by same instructor who had been booted from UTD, or anything to that effect? Entirely unassociated and in different setting?
You call it "RD out of the box" and I see it as RD in actual use.
I don't mean to be pedantic, but "By the book" is the meaning I'm endeavouring, to be certain. "out of the box" was maybe inaccurate localization on my part. The reason it's relevant to reiterate that UTD encourages adaptation, is because it means you can subscribe to whichever level of deep stop emphasis you interpret available scientific evidence to support, and use that emphasis level in Ratio Deco. Ths isn't too much unlike a GF-setting at least in that regard.
Almost all involved mental errors on the part of the diver, and they were to a person quick to point that out.
From other conversations, I'd sensed as much.
Look, I feel you and I can probably agree that what we're discussing here, is not whether a given deep stop level is optimal, but rather the nature of RD versus using a computer and specifically, diving without a computer. Correct me if I'm wrong.
I think it makes sense to make that disambiguation, as it doesn't blur the picture of our discussion so as to imply a statement to the effect of "using a deep stop emphasis too great is dangerous".
Rather, I feel - again, correct me if I'm wrong - we're approaching the core of what you're saying with this:
The person using Ratio Deco is probably always the weakest link, and that's the real problem with it.
I agree and I disagree, bu more importantly, I understand what you're saying.
I agree, on a general level, that the diver is the weakest link, and it stands to perfect reasoning that this applies when using RD, too. As olive branches go, I don't have a problem with that statement.
But that's where our agreeing on the matter ends - I personally use RD from the start to develop divers.
That is, "identify the weakest link in the chain", if you will, and develop it.
I genuinely have concerns about large-scaling a culture of "masking" weaknesses - here by adding a computer because diving without one is perceived as dangerous - as I see that the weakness will simply manifest elsewhere.
If I'm short on situational awareness and adherence to diving within my comfort zone, I perceive that as a
much greater risk source than DCS from a dive with deco emphasis probably a bit too deep.
That said, I exercise vigorously, have very little body fat, am in my early 30´s, don't smoke, eat full-meal plant based and generally hydrate well. My doctor year after year insists that my blood is "optimal". So while I can probably handle a minute difference in BIPA, I can still drown in an instant, lose orientation or switch to the wrong gas. I feel the latter are related to situational awareness and diving within my comfort zone.
Elsewhere, John linked to
this article which touches on the matter and lists four issues that I believe you might agree can be said to sum up the concerns about RD. Correct me if I'm wrong in that.
Note, I'm paraphrasing - heavily. For the original wording, please see the link.
1) Can't stay within maximal depth
2) Can't maintain ascend rate
3) Can't maintain depth accurately
4) Can't tolerate extremely basic arithmetics while diving
If these four are the problem, then I certainly would like to add a comment or two, as you may imagine.
First, if I can't maintain acute discipline with my maximal or minimal depth, I feel that's a ppO2-related issue rather than DCS one. Punishment would find me, and this touches on such a basic skill level that I feel adding a computer for redemption is actually wildly problematic. The oblivious diver is in dire straits here, and is at such a low level of capacity for diving that I really feel something has gone
terribly wrong if that diver is doing tech dives.
I think the same holds true to some level, for bullets two and three.
As bullet four goes, I feel it's a non-argument because the mistakes one would need to make are so rudimentary and particularly because
everyone in the team would need to make them. Identically, that is.
If two divers diverge in stop depth calculation by, say, 5 minutes, surely alarm bells would be ringing.
To maintain this is a problem is, in my view, just as sought as maintaining that diving computers in a team is dangerous because they could all fail.
Perhaps if you could provide that study I keep asking for, I could have a more enlightened opinion. You haven't, so I have to rely on the evidence I can see.
I ask genuinely what you would like to see, as I don't feel I understand that.
If you're asking for a study that shows RD is the optimal approach to decompression from a physiological point of view, I'll be the first to state categorically that to my knowledge no such study exists. I don't see a conflict in that, for my part.
But it probably has to be seen in light of the section I wrote, above.
You see, the drunk driver scenario really fits. It's my opinion that putting on Scuba gear eliminates 15/20 IQ points. Splashing another 15/20, and you can keep deducting points for every atmosphere you descend. The problem is people don't "feel" stupid: they just are. Their Bovine Index equals 1, and they don't even know it. Ergo, relying on a diver's memory is an invitation for error and getting bent. I wish I could count how many times I forgot to set the bezel on my dive watch on first descent, or the witness mark on my depth gauge. How the hell do you expect me to average depths consistently and competently, especially when I've got the IQ of a cow at a hundred feet? It's not in me and I find any protocol/strategy that requires me to do so problematic from the get-go. In fact, those were the kinds of errors that the people who got bent on RD kept referring to. Me? I want something that compensates for my depth induced ADD and that's a PDC. Can I dive without one? Sure, but I'm not going to do a deep deco dive. I know and honor my limits. RD is one of those protocols/strategies that I can live without. Besides, I don't dive to compute my deco obligation: I dive to look at the pretty fishies and appreciate the friend on my wrist that handles that hideously tedious crap for me. Sure, I check her work, and so far it's been great.
And I respect your opinion.
It stands in stark contrast to statements maintaining the dangers of RD.
We don't see things the same way, and that's okay, too.
BTW, I assume that you've never been bent
Correct.
nor have any of your dive mates, right?
One gas rash after a suit flood in ice water. Other than that, nada.
It seems to me that in this thread, the most ardent proponents of Ratio Deco think people should use it because...
1. It is not as bad in comparison to other systems as people think--the other algorithms are not that much better
2. It is not as dangerous as people think.
3. It is not as hard to do all the math and other calculations while diving as people think. Anyone can do it.
4. A lot of the people who get bent using it made mistakes with the math or other calculations, so it is not the fault of Ratio Deco but rather the fault of the divers who were not able to do the math--even though the math is so simple anyone can do it.
I disagree with this statement.
This looks like the blueprint of something I'd say if someone insisted to me that RD was dangerous.
If and when I'm asked what benefits I see, the focus of the argumentation lies elsewhere entirely.
But so does the nature of the query, so I feel that's natural and fair.
Nope. It is a very valid comparison. If you know the effect something has and you don't like the effect, you don't have to know any more about it.
You berate Pete because he does not have RD training, implying that if he only had the RD training, he would love it. I have the RD training and I do not like it one bit.
So long as we're disambiguating across deep stop emphasis (relevant to a thread on the Spisni-study) and diving computer-free (not relevant to the Spisni-study, and not isolated to RD)
I point out that there was not adequate knowledge behind the statements that RD is dangerous, and I stand by that. That's not the same as implying he, or anyone, would love RD if they had the training, to be sure. But the training is a prerequsite for a more comprehensive understanding.
If you bugger up the depth using ratio deco you would have also buggered up the depth using tables.
Exactly.
