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

[Basking Ridge Diver]

It's a common-sense principle, not a mathematical rule.

A percentage could work in all cases. For example 10% is easy to follow and could be implemented round up to the nearest minute.

But I think we digress - NDL's are not a clear Red Line - but a Grey Area for each individual. You need to know your risk tolerance and your honest assessment of your physical attributes. If you are not in shape and you are prone to forgetting your situational awareness including monitoring your gas and NDLs. You may want to dive more conservatively than 25%...

But this is all being an adult diver and figuring out what is best for you. Because when you get hurt - all you need to do is look in a mirror and explain to yourself and your family what happened.

Take your training or venture into lite deco knowing the risks.

 

[KenGordon]

I think this is somewhat of a red herring. They may all say that, but do any of them actually give a definition for "diving conservatively"? It's hard to accuse someone of second guessing if you haven't actually given them anything to be measured against.

It used to be the case that computers were conservative and tables less so. So diving the computers was instrinsicly conservative. But now it is popular or dial your own conservatism, or more likely lack of conservatism.

Also, back too the where the other thread had gone, it is the instructor's job to impart what conservative means.

 

[KenGordon]

A percentage could work in all cases. For example 10% is easy to follow and could be implemented round up to the nearest minute.

Not all NDLs have the same risk, even within the same table.

 

[DevonDiver]

NDL's are not a clear Red Line - but a Grey Area for each individual.

Think about what you just said...

No-decompression LIMIT

It's a very definitive line, dictated by the model that represents a very reasonable statistical assurance of DCS symptom free diving.

DCS risk is, of course, not a red line. There are dozens of known, hypothesised and yet to be known factors that influence individual susceptibility.

Nonetheless, staying inside (or further inside) the statistically defined limits accounts for those factors with a high degree of confidence.

Choosing to push, or exceed (!) those limits drastically reduces that confidence.

Very experienced divers have the opportunity to learn their individual tolerances more intimately. More dives equals a larger individual sample size...and more feedback on personal physiological capacities to cope with super-saturation and off-gassing gradients.

Dozens... even a few hundreds... is not significant experience in that respect.

There are a few... a very few... divers who seem to be less inclined to DCS symptoms. It'd take 1000's of dives to know confidently if you're one of them.

Many divers are average... and are well protected by NDL limits. Even then, there are a myriad of pre-disposing factors that can become evident.

It might take a lot less dives... especially if pushing/exceeding NDLs... to learn if you were a diver more inherently inclined to DCS. You'd learn whilst led in a chamber.

 

[Lorenzoid]

The admonishment I recall from my OW training with regard to conservatism was simply (over simply, of course) to "stay away from the edges of the table." The very last block of the table is highlighted in some ominous color/tone, and the next block or even two blocks back are also highlighted. I got the impression that straying into the highlighted ends of the table was something to be avoided, though we were taught procedures (e.g., safety stop becomes mandatory and/or extended) to deal with it should it happen unintentionally. The hard, visually impressive limits of the table provided a good learning tool, though I now realize those limits are as ill defined as any. With a computer, there are no such pressure groups/blocks to give a diver a visual sense of how close is too close, and adjustable conservatism features make limits even more vague. However, nowadays diving a computer set to "medium" conservatism, I still give myself a few minutes of safety margin from whatever NDL it may give me. I realize I could just as well set it to "high" conservatism and dive until it counts down to zero, but that old PADI table training is just so ingrained in my mind. I see that as a good thing.

 

[boulderjohn]

hat is just too funny. I lied, give me one more post. So after all that research, PADI offers an undiveable internet solution to IRL?

No, real people learn by doing in real life. First by someone's core principles under expert supervision, then by branching out if the student chooses that path.

Pilots use flight simulators for their training all over the world. Virtual dissections now introduce students to anatomy. It is rapidly becoming the standard for all training processes.

 

[Basking Ridge Diver]

Think about what you just said...

No-decompression LIMIT

Ok - think about this - each computer and each algorithm derives a different NDL...
So unless I am missing your point - your computer or your table derives that NDL... I get that but based on your purchase you can have a different NDL and I think in his own way that is what LowViz was trying to say.
With so many different NDL's you are telling me what? That there is a single NDL? Of course not.

 

[redacted]

Not all NDLs have the same risk, even within the same table.

Can you explain that? Can you provide any supporting data on the different risk levels?

 

[redacted]

Ok - think about this - each computer and each algorithm derives a different NDL...
So unless I am missing your point - your computer or your table derives that NDL... I get that but based on your purchase you can have a different NDL and I think in his own way that is what LowViz was trying to say.
With so many different NDL's you are telling me what? That there is a single NDL? Of course not.

While a diver may carry and refer to an array of NDLs (tables and computers), for a given dive they must end up choosing a subset that they follow and a subset that they violate. Subsequent dives should be conducted using only the subset that was followed on all active previous dives.

Most recreational divers conduct their dives with only a single NDL.

 

[Scuba J7]

Can you explain that? Can you provide any supporting data on the different risk levels?

Would a higher pressure group(on dive tables) mean more risk for DCS? Depending on depth differing NDLs put you into different pressure groups.