Place of dive tables in modern diving (Split from the basic thread)

[Kevrumbo]

That's not correct. This multi-day tissue residual gas stress accumulation, is simply not significant or even noticeable. It's grossly over hyped. Some simple checking with math reveals little or no valid difference pressures across several days. Take a look. . .

Now experience shows there clearly is some lingering side effects of multi-day exposures, and a rest or extra care is always needed.

But it does not involve a build up of excess tissue stress. I think the real cause of multi-day injury, is some other tissue stress or fatigue is at play, still yet to be explained.
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Ross, these tissues are a source of Venous Gas Emboli (VGE) in which the loading, and then unloading in a surfacing supersaturated post-dive state after a sequence of consecutive days of multiple dives per day can be a significant cause of decompression stress. (See Decompression Accident in North Sulawesi )

If it's so grossly over hyped as you say, then why are divers with a suspected PFO at increased risk for DCI?

Mending a broken heart (or how I found out I had a PFO) – Dive Gainesville

 

[rossh]

Ross, these tissues are a source of Venous Gas Emboli (VGE), in which loading and unloading in a surfacing supersaturated post-dive state after a sequence of consecutive days of multiple dives per day can be a significant cause of decompression stress. (See Decompression Accident in North Sulawesi )

If it's so grossly over hyped as you say, then why are divers with a PFO at increased risk for DCI?

Mending a broken heart (or how I found out I had a PFO) – Dive Gainesville

Kevin, You are overlapping un-related issues.

The point in discussion, is the long held belief that we divers accumulate some excessive tissue saturation over several days, and that directly causes injury. But that acumulation is not the case. If the basic on / off gassing formula are to be trusted, then they show the build up does not exist. So I suggest that maybe some other factor is the bigger issue at fault causing multi-day injury.

The same myth is made about deeper stop on gassing, and a quick check of the actual math numbers, shows that is over hyped too.


People with PFO's are at a disadvantage - their circulation plumbing is short circuited and they cannot off gas as fast as a normal system.


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[Kevrumbo]

Kevin, You are overlapping un-related issues.

The point in discussion, is the long held belief that we divers accumulate some excessive tissue saturation over several days, and that directly causes injury. But that acumulation is not the case. If the basic on / off gassing formula are to be trusted, then they show the build up does not exist. So I suggest that maybe some other factor is the bigger issue at fault causing multi-day injury.

The same myth is made about deeper stop on gassing, and a quick check of the actual math numbers, shows that is over hyped too.

People with PFO's are at a disadvantage - their circulation plumbing is short circuited and they cannot off gas as fast as a normal system.

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Why then Ross, for the no-fly recommendation 18 to 24 hours after a multidive consecutive day series? That is, if you claim there is no significant build-up or accumulation of tissue saturation?

Ross, they are not unrelated issues -VGE bubbles and decompression stress; repetitive loading and unloading of inert gases in real physical tissues & blood and the response of the body's immuno/inflammatory system; PFO and DCI pathology; altitude and no-fly times- all are real analog, diagnostic, and researched somatic phenomena that you cannot dismiss as myth or contend as due to some yet "unexplained" factor within your mathematical model.

 

[AfterDark]

Did I slip into a tech site?!? I was reading a thread in the basic site about tables and PDCs, not deco theory.

 

[lowviz]

Did I slip into a tech site?!? ...//...

No. But the Twilight Zone, quite possibly...

rossh's response was clearly tempered for newbies in Basics.

 

[rongoodman]

Did I slip into a tech site?!? I was reading a thread in the basic site about tables and PDCs, not deco theory.

Is that a problem?

 

[lowviz]

Nope, no such thing exists. No deco here, move along now...

 

[lowviz]

I guess I don't understand what the possibilities of getting bent on a single AL80 has to do with the buddy system. Pretty much no newbie would be able to get bent on a single AL80.

sorry, had to re-read the end of this thread a couple of times to get it. Yes, you can unless you adopt a buddy system that requires you to reserve gas for your buddy should he/she lose all of his. Then you don't have enough to hurt yourself unless you try something REALLY stupid.

Works both ways, you get the same benefit from your buddy's reserve gas.

 

[rossh]

Why then Ross, for the no-fly recommendation 18 to 24 hours after a multidive consecutive day series? That is, if you claim there is no significant build-up or accumulation of tissue saturation?

Ross, they are not unrelated issues -VGE bubbles and decompression stress; repetitive loading and unloading of inert gases in real physical tissues & blood and the response of the body's immuno/inflammatory system; PFO and DCI pathology; altitude and no-fly times- all are real analog, diagnostic, and researched somatic phenomena that you cannot dismiss as myth or contend as due to some yet "unexplained" factor within your mathematical model.

Once again, if we look at the actual math, we will see a strong correlation between No-Fly time recommendations, and the residual supersaturation times. The idea behind no-fly times, is to get every recent diver passenger back to the same baseline as the non-diver passengers.


You are trying to justify the cause with a result, but the presumed cause (excess multi-day residual tissue pressure buildup) is not present in the amounts you implied, or amounts that are significant.

I think there are more (unexplained physiological effects) as the leading causes to multi-day DCS injury than what has been presumed in the past.

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[MargaritaMike]

No. But the Twilight Zone, quite possibly...

rossh's response was clearly tempered for newbies in Basics.

I don't think so.

Cheers -