Mass confusion about computers????

[CAPTAIN SINBAD]

You do know, don't you, that at this point the only agency I know of that still plans decompression based on that debunked oxygen window theory is UTD? (That's the origin of the S-curve.)

From what I recall of the updated Ratio Deco 2.0 they had gotten rid of the S curve and time from the middle was being used to pad the shallower stops. It is closer to a Buhlmann profile than the original. As we look at the evolution of ratio deco, I think the future of Ratio Deco is an even shallower first stop and possibly more time from the middle to pad the shallowest stop.

 

[KenGordon]

In my own case, SB led me to watch a video of a presentation by Simon Miller given in South Africa that I wouldn't have likely found otherwise; other SB discussions led me to buy and read (more than three times now) Deco for Divers; that led me to follow and then dig for threads on SB and various rebreather forums about the NEDU study; my effort to try to separate the personalities from the postings in all those threads improved my own awareness of deco theory, led to buying a different PDC, continuing to compare the new computer to the old one on over 100 dives specifically looking at the "heat maps" generated by a model for tissue loading through the dive profiles.

I'm not sure SB was the place I got advice, exactly, but it sure was the place that brought me information and links and discussions to consider.

You would have been a couple of years ahead in all those things following Rebreather World.

Almost all the other forums are more finicky about deco theory and tend to have memberships who are largely doing deco diving rather than largely doing NDL limited diving.

 

[KenGordon]

OK @KenGordon

We'll leave it at that. I have something thats works very well for me, hope others find the same.

Good diving, Craig

I do not understand how you are quoting yourself here. You raised your history in support of a position. That makes it for anyone to question.

 

[tursiops]

Almost all the other forums are more finicky about deco theory and tend to have memberships who are largely doing deco diving rather than largely doing NDL limited diving.

This is really the point, isn't it? If one is doing NDL diving, then some of the nuances relative to deco diving are irrelevant. If you don't like DSAT for deco, for example, I'm with you 100%. It was not designed for deco, was not tested for deco, works horribly for deco. So, don't use if for deco. But, also, don't denigrate it for NDL diving just because you don't use it for deco diving.

 

[KenGordon]

Thanks for actually trying to answer my question, but I'm not at all convinced by your answer. To be convinced, you'd have to show me a few pieces of evidence:
(1) there is a correlation between getting bent and the kind of computer you are using, and (2) it is DSAT-based computers that lead that correlation. Also, your use of agressive might better be replaced by least conservative. ALL the modern recreational computers are conservative, especially compared for example to the older Navy tables.

If you want some pure speculation, how about this: people getting the bends are those least likely to follow their computers, especially on bottom times, ascent rates, and surface intervals. I speculate those are Suunto users, because those computers are ubitquous, can be quite cheap, and have weird rules for their use.

I am not claiming that DSAT computers are particularly dangerous. However, if one computer has a longer NDL time than another and divers use that time and increased exposure results in increased risk then it seems to me those divers are subject to increased risk.

Nobody tracks how many dives happen, how many people get bent or what computers they were using, so no evidence is available. What I am saying is that what you and Scubadada put forward is not evidence either. You cannot say one way or the other that DSAT is safe based on having a DSAT computer on your person and then doing dives shorter than it allows.

Nobody gets bent deliberately. If people are ignoring their computers it is either because they really don’t understand it or they have decided it is too conservative and may be safely ignored. The later seems likely to come from repeatedly reading that said on the Internet.

By the way, tables are not necessarily more aggressive than computers. They make different assumptions and some of those are key. Number of dives per day is one, rounding another and especially the square nature of the dive. If you tried a four dives a day holiday diving schedule on navy tables I think you’d get less bottom time than a typical computer.

 

[tursiops]

However, if one computer has a longer NDL time than another and divers use that time and increased exposure results in increased risk then it seems to me those divers are subject to increased risk.

You are missing a MAJOR point: which computer you use is not nearly so important in risk mitigation as staying within the NDL, ascending slowly, doing a safety stop, staying hydrated and warm, etc., all the things that much more contributory to DCS. Your argument is analogous to saying that if I'm going 100 mph down the highway while drinking a cup of coffee and reading text messages on my phone, that my risk is higher if my car seat is poorly adjusted. It may be marginally true, but it is really not the risky thing to pay attention to.

 

[lermontov]

You are missing a MAJOR point: which computer you use is not nearly so important in risk mitigation as staying within the NDL, ascending slowly, doing a safety stop, staying hydrated and warm, etc., all the things that much more contributory to DCS. Your argument is analogous to saying that if I'm going 100 mph down the highway while drinking a cup of coffee and reading text messages on my phone, that my risk is higher if my car seat is poorly adjusted. It may be marginally true, but it is really not the risky thing to pay attention to.

No- Hes including risk mitigation in his comment ..

if one computer has a longer NDL time than another and divers use that time and increased exposure results in increased risk then it seems to me those divers are subject to increased risk.

and if youre driving your car at 100mph for longer then your risk increases -all other factors being equal

 

[tursiops]

No- Hes including risk mitigation in his comment ..

if one computer has a longer NDL time than another and divers use that time and increased exposure results in increased risk then it seems to me those divers are subject to increased risk.

and if youre driving your car at 100mph for longer then your risk increases -all other factors being equal

Whatever.

 

[DerekR]

While hydration is often touted as a factor in preventing DCS, no real connection has ever been made. It is a tenuous, and completely unproven theory.

 

[tursiops]

While hydration is often touted as a factor in preventing DCS, no real connection has ever been made. It is a tenuous, and completely unproven theory.

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