Is a computer actually necessary?

[Kendall Raine]

To jviehe: I know what article is about since I also read it. It is a peer reviewed article and so what's in it, including the statistics, can be assumed to have been peer reviewed. Without reading the citations at the end of the article, there is no way you can claim with any authority it is not substantiated. Believe whatever you want to, I don't care either way. The actual number wasn't the point to start with.

To Uncle Pug and Blackice: You guys have it exactly.

This thread is beat. Over and out

 

[Diver0001]

String once bubbled...


However the human brain is far from capable of performing the required calculations and sample rate that even a simple computer can. If you can show me a diver who can update his mental dive picture at 0.1 second intervals with accuracies to 3 decimal places throughout the entire dive i might believe you. Otherwise i dont.

Uh..... why would you even want do do that? A dive can be seen as a pattern or a curve which is influenced by many variables including things that the computer can't know about like how you feel. Computers calculate using brute force on a very simple model because they can't fathom patterns very well. Your brain, on the other hand, does this with incredible ease.

It's a little bit like playing chess. You can play a pretty decent game of chess without having to calculate every possibility in what computer people call the "solution" tree. In fact, if you tried to play chess like a computer does then you'd never get anywhere.

R..

 

[fgray1]

My brain is starting to hurt.

 

[String]

The fact still remains that both tables (all of them) and computers (all of them) are just trying to follow statistical models. Again, a computer is capable of adhering to that model far more accurately than a human is on a dive.
No model is perfect but a lot of them are certainly safe enough to use so therefore why deliberately hinder yourself by making a very rough approximation for it ?

Regarding tec diving i agree that most rec computers algorythms are not really optimised for it and can lead to huge stop times and so forth but from the original poster in this thread about being new im assuming he means rec diving as only recently qualified not multi gas trimix dives. The only real computer i can think of for proper tech diving like that at the moment is the VR3.
For non severe deco diving im quite happy to use my Vyper though and sit it out (typically never more than about 15 mins of stops) but again i carry tables as a back up. During comparisons ive done my tables and computer are within 1 min of each other for stops for the same dive if its square as well (and yes the tables i use are designed for deco).


Im not advocating the "jump in and see" tactic some people are on about but there really is no harm in jumping in after looking on tables and carrying a spare set. Worst case scenario, computer breaks, tables get you out, albeit after a longer stop than would really be neccesary (again due to to computer sticking to the model far more accurately whereas a human assuming a square profile table).

 

[MikeFerrara]

Rapid samplin of a pressure transducer and a bunch of fast number crunching don't help if the number don't mean anything.

Just within Haldanian models....

Grab a DSAT table, Buhlmann, Navy, NOAA and whatever else you have availabe. Look at the NDL's on them. Notice how at some depths you'll see deviations of like 40%. Which one is right? What good is all that precission if we don't know what the real NDL is? Well, if there was such a thing. Which one does your computer use? Which do you prefer? How big is the hill you need to climb with your gear after the dive? How did you feel after your last dive?


Two freinds of mine did a dive. They're "good" divers. They followed their computers and did a "slow ascent". they even extended their "safety stop". One was fine and one was badly bent. The computers were hapy though. They couldn't understand it. I saw the profile and there's no way I would ever do that dive the way they did. I ran the dive in decompression software and depending on how I set the use settable parameters I can get it to tell me there is no required decompression and I can get it to show they needed another 2o minutes or so. Which is right? I can tell you this, what the computer said was wrong because it didn't work. I hope they didn't pay too much for em.

 

[Rick Murchison]

Is a computer actually necessary?
No.
Useful?
Yes.
Believable?
Sometimes... often... you just have to know when.
The "end-all" and "be-all" to guide you in your diving profile?
Absolutely not!
Do I use one?
Yes, sometimes two.
Rick

 

[fgray1]

BEST ANSWER YET
MY COMPLIMENTS
AND THEY DON'T COME EASY.
FRED

 

[jviehe]

Rick Murchison once bubbled...
Is a computer actually necessary?
No.
Useful?
Yes.
Believable?
Sometimes... often... you just have to know when.
The "end-all" and "be-all" to guide you in your diving profile?
Absolutely not!
Do I use one?
Yes, sometimes two.
Rick

I think it would be more accurate, however, to say the computers are almost always believable. Yes, there have been some models with glitches, but there is no evidence that dive computers en masse have displayed incorrect information.

 

[Uncle Pug]

The dive computer does present some real downsides not the least of which is erroneous information.

Even if the information displayed where error free... and let's assume something we know to be untrue... even if the information were actually correct (the two are not the same) the real problem is this:

The information supplied by the dive computer is not the salient information needed. Presenting and prominently displaying information that is false at worse and superfluous at best is not helpful.

To the Compuphiles the issue is a choice between dive tables and dive computers. Those who proudly claim to carry both on their dive are still widely missing the point.

There is something more important than *NDL*.

 

[Rick Inman]

Uncle Pug once bubbled...
Those who proudly claim to carry both on their dive are still widely missing the point.

Far more recreational divers are diving less conservative dive profiles using computers today then were before computers (like in the 60's and 70's). The question is, are more, or less people (both actual and percentage) getting bent today then in the pre-computer era? I'm not being smart here (never been accused of that), I really don't know. But IMHO, THAT is the point.