"Riding your Computer Up" vs. "Lite Deco"

[DevonDiver]

No fudge-deco involved at all.

It is all about recasting the most aggressive recreational NDL diving into conservative deco diving. Same limits, when the aggressive NDL diver times out, so does the lite deco diver.

Where is the problem?

Where did you get that from?

There's no stipulation or prohibition on algorithm or conservatism in the Tec40 course.

An 'aggressive' diver with Tec40 would/could time out later than if sticking to NDL. However, they'd potentially benefit from safer surfacing tensions as they'd have the option to use 50% on ascent for their conservatism (an option they have, not a mandated requirement).

I'm not surprised that additional training would be suggested. After a decade of light deco, I will pass. Nobody asked me for my Tec 40 cert.

I don't pass judgement, but I've heard simular sentiments from a legion of complacent and relatively (ability versus dives done) incompetent 'experienced' divers.

Of course, there's exceptions... but I see lots of deluded divers, full of bravado as to why they didn't/don't need this training or that equipment.

Diving by luck, enjoying by ignorance and waltzing ever further down the path of 'normalization-of-deviance'...

Is there no course that specifically teaches back gas deco considerations? Does some common-sense organization like BSAC cover this?

I hate to keep repeating this... but Tec40. It's not accelerated deco training. You have the option to use 50% for conservatism only. That's a tool you can elect to use, not any type of mandated requirement.

Because the other option is the School of Hard Knocks? Learn by surviving your mistakes?

Decompression is not a scenario where it's prudent to learn from mistakes. Anyone content to do so must desire contention for future Darwin Awards...

It's no coincidence that technical training in every agency includes education on 'mind-set'.

So now we can sit back and wait for examples on the necessity of that education from recreational divers who 'know better'.

 

[DevonDiver]

.. but I do use both a 'technical' Suunto the HelO2 which supports 8 gasses and helium and a Zoop which only supports one gas and would not be described as 'technical'. If diving only one gas they behave the same way...
... If I plan a dive with the Suunto planner it usually matches reasonably well.

Not a great advert for Suunto as technical diving instruments mate...

 

[DevonDiver]

Why does everything need to be taught?

Because paralysis sucks.

 

[uncfnp]

I'm guessing that there is a problem using conservative recreational computers and deliberately pushing them into deco. If I understand correctly how these computers work, if you go into deco they 'assume' that it was unintentional, and inflict penalties as such. IOW, the computers' algorithms assume that the diver made an error, and because of that they may add additional required surface interval time, or do something else intended to change the diver's 'reckless' behavior in unintentionally going into deco. Maybe my understanding is not correct.

Like Boulderjohn I keep the Petrel in tech for all my dives but set for ultra conservative. The Cressi is set at its most "liberal." I don't have a control computer for true comparisons but I can not say that I have seen a penalty on the Cressi for deco-that is cleared. The most it seems to do is add the safety stop to the deco time which the Petrel does not. And I don't get as much credit for ascending so the total time to clear deco on the Cressi is usually longer,

This, above. There is no statistical or other empirical evidence that diving a "liberal" computer within NDL with a safety stop is in any way safer than diving a more "conservative" computer and following deco obligations, on the same dive profile, for recreational diving. Conservatism is theoretical and might provide a comfort level for those who choose to use it, but there's no evidence that it reduces DCS risk in this context.

Oops, Andy posted before my reply, which was to Halocline and not to Andy's post above.

I think there is evidence both research and empirical that conservative does matter. Andy can correct me if I am wrong but I believe there are bubble studies that have documented higher grade bubbles in more agressive dives vs less bubbles in conservative. If you are in the camp that agrees that bubbles and DCS are linked this may be important to you. I assume there is also at least some empirical evidence as well since experts in dive medicine will usually, in my experience, recommend "conservative" diving to those of us at increased risk.

Now whether treating recreational dives as tech dives adds any benefit over an aggressive liberal profile or "riding the computer", I have nothing to offer except logic and my own anecdotal evidence (an we all know what anecdotal evidence is worth).

 

[Bob DBF]

Diving by luck, enjoying by ignorance and waltzing ever further down the path of 'normalization-of-deviance'...

If one is ignorant and diving by luck, they wouldn't be waltzing ever further down the path of 'normalization-of-deviance' since they have no proper procedures to deviate from.


Bob

 

[DevonDiver]

If one is ignorant and diving by luck, they wouldn't be waltzing ever further down the path of 'normalization-of-deviance' since they have no proper procedures to deviate from.

True... I stand corrected.

Deviants from the offset... nothing to normalise.

 

[DevonDiver]

I think there is evidence both research and empirical that conservative does matter. Andy can correct me if I am wrong...

I don't believe that needs correction.

"I would have gotten away with my spurious internet theories, if it weren't for those meddling Doppler technologies... "

 

[stuartv]

Ha!

I love the differing viewpoints in all this. Nice reminder that there are *serious* rec-only divers out there.

The owners of one of my local shops are a husband and wife. They teach a lot. They dive a lot. They have no tech training zero interest in getting any.

Yes, there are plenty of *serious* rec-only divers out there.

@stuartv True. . . . but is it not equally as flippant for a 10-20 dives per year diver to start dicking around doing 'lite' deco because their sense of entitlement exceeds their knowledge and caution.. . . and the admitedly crappy, bargain bucket, 3 day OW course they waltzed through a decade before eventually placed some 'grossly unfair' restrictions on their Lemming-like desires to personally dispprove the Gas Laws of Physics?

Am I flippant? Do you have any idea what I've spent on diving tuition and equipment over the years? LOL

I'm far from flippant... I just don't support any notion of dumbing-down diving to placate a demographic whose sense of entitlement outstrips their willingness to make a reasonable commitment to obtain the necessary resources to ensure safety at their chosen parameters of diving endeavor.



... like "2 more minutes in the eel garden at El Aquila".

You know, you don't need technical training to figure out your RMV. Nor to run a dive profile in Multi-Deco and figure out how much gas you would need, even for a deco dive. Nor to understand what Gradient Factors are.

I just don't see anything AUTOMATICALLY, INHERENTLY wrong with someone that has no formal tech training doing dives with a few minutes of deco. You implied that anyone doing that without formal training is foolish. I don't think that's fair. I think it's entirely feasible to learn how to do that safely on your own.

 

[Dizzi Lizzi]

You are new and are saying all the things you were probably taught in a class

Ha! In class I could give the correct answers, but I did not really understand the theories. Scary!!
Deco was just kinda glossed over. SB is where I've received the majority of information. Like this:

Being in decompression is a very thin bright line when it is drawn by a computer, but in actuality it is a wider, fuzzy line. The ambiguity in the line is based on individual differences in physiology, exertion level, thermal condition, level of fatigue, which computer they are using (and what parameters have been selected) and probably many other issues which are not well understood....but if you push an aggressive profile on your computer and you are cold, tired and out of shape and recovering from a flu, you are probably more likely to get bent on that dive than one where you were relaxed, warm, rested and actually skipped a one minute

Hopefully I will get a few hundred more dives in, and ok I will do my best to read entire threads before commenting...or at least commenting before they are so big . Honestly sometimes it's so over my head I get lost. But compared to where I was last year I'm getting it...slowly.

 

[lowviz]

Where did you get that from?

There's no stipulation or prohibition on algorithm or conservatism in the Tec40 course. ...

*sigh*

You are arguing beyond the scope of this thread again. I haven't taken Tech-40, I took AN-DP after OW. If you re-read my OP, you will see that the only deco that I'm discussing is the deco requirement one gets if one replaces a purely recreational dive (done aggressively using an aggressive DC) with a highly conservative DC/algorithm/plan that will allow for deco. Same dive profile, same dive. Same thinking put into practice daily around the planet: Buy an aggressive DC and max it out under NDL rules.

...//... I just don't see anything AUTOMATICALLY, INHERENTLY wrong with someone that has no formal tech training doing dives with a few minutes of deco. You implied that anyone doing that without formal training is foolish. I don't think that's fair. I think it's entirely feasible to learn how to do that safely on your own.

I agree.

And if you do that, you find yourself standing on the other side of one of those many "lines in the sand/fences" where it actually is a bit safer (better practice?) than the corresponding spot on the rec side of the fence. Problem is, and I think that this is what is driving Devon Diver nuts, is that it is way to easy to start wandering around once you go over there. It takes a large dose of self-discipline to stay in your little spot over there. But one shouldn't even be diving without such discipline.

It appears that you and your LDS have been able to do just that and I don't find it the least bit surprising or offensive.