Is a Dive Computer necessary?

[boulderjohn]

No, understanding tables does not imply a deep understanding of dive physiology just like mastering addition does not mean you will join AP calculus. Nonetheless I still firmly believe that a diver trained on tables and square profiles will have a better understanding of nitrogen accumulation and decompression. More importantly it imparts the fact that the dive computer and it's alogarithms are not absolute and that at all times common sense should trump. Something that someone conversant with tables will best appreciate.

How on earth does learning tables teach you that the dive computer is not absolute and common sense should trump? That one has me totally mystified. How do you know that someone who has learned the tables must have a better understanding of nitrogen accumulation than someone who learns on a computer? As I said, my whole training on this comes before I teach either tables or computers, and I teach it the same way for either class.

Perhaps the most celebrated book explaining decompression theory today is Mark Powell's Deco for Divers. He does a great job explaining decompression theory in great detail without once teaching how to use tables to measure it.

By the way, you comparison using arithmetic and calculators is a false analogy. In order to get by in today's world, unless you are in a pretty much no math situation in your life, both the ability to compute by hand and the by calculator are necessary life skills. Schools still teach both, and for good reason. To a certain extent, you must have the basic manual competition understanding to use a calculator. But that only does so far. In math classes, you probably learned how to calculate square roots by hand. Do you think the ability to do that by hand is a critical skill, or is it OK to use the calculator to find that for you?

In contrast, there is no need to understand the tables in order to use and understand the computer. More than 100 years ago, John Haldane tested goats in order to find a way to make people safe from DCS on ascent after being under pressure. He had to figure out a way to make the results of his research usable to the population that needed it, and he created tables for that purpose. If he had done his research in a more technically-advanced era, he might have created the first computer algorithm for that purpose instead. If he had done that, there is a good chance no one would have invented tables. If that had happened, none of us would even know what tables were, and no one would be arguing that you need to know the tables in order to understand what the computer is doing.

 

[Nemrod]

If you buy a computer, do not bother to get an air only model. Get something that will handle at least nitrox or you will be buying yet another computer before long.

N

 

[Craig66]

Boulderjon, we will have to agree to disagree. As we move into a world where the computer does more and more for us, we will have to see whether basic skills go unmissed or whether we mourn their loss.

I find it interesting that the original poster who was only trained on computers posed the following question: is a dive computer necessary? Given that he has no training on tables the answer should've been: H-ll yes what else are you going to use.

Perhaps his issue was that he was not trained by you or perhaps while your theory is entirely sound the reality not so much. I tend to dwell in reality.

Well, I am off to a wedding which nowadays has not yet been replaced by a computer and this is a good thing, although I am sure others would beg to differ. I will however be sure to post my status on Facebook to meet the needs of the New World.


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[boulderjohn]

Boulderjon, we will have to agree to disagree. As we move into a world where the computer does more and more for us, we will have to see whether basic skills go unmissed or whether we mourn their loss.

I find it interesting that the original poster who was only trained on computers posed the following question: is a dive computer necessary? Given that he has no training on tables the answer should've been: H-ll yes what else are you going to use.

Perhaps his issue was that he was not trained by you or perhaps while your theory is entirely sound the reality not so much. I tend to dwell in reality.

Well, I am off to a wedding which nowadays has not yet been replaced by a computer and this is a good thing, although I am sure others would beg to differ. I will however be sure to post my status on Facebook to meet the needs of the New World.

I have no idea how this person was trained, but I have the concerns I expressed.

If the person took the computer version of the PADI course, that person would have had to read and answer questions in a spec ail book dedicated to computer usage. He would have learned the things he does not apparently know. He would have had access to a very sophisticated online simulator that would have gone into how a computer works with decompression in great detail. It does not sound to me as if any of this happened.

 

[gopbroek]

Here is a Comparison: automobiles used analog mechanical carbs for many years. The science and engineering that was developed was awesome. Then computers came out and after a few years of growing pains the gains in economy and performance were clear. Square profile tables are a very good basic safety tool but they are like a chainsaw compared to scalple. This is not to take away from science of the tables but the built in limitation is for the dumb human to constantly re-calculate for a real life multi level dive.
Computers can fail, been there done that, but unless you buy cheap crap (like me) it is really a low probability but for peace of mind you can carry two at less than than $200 each, used, it really is a pretty cheap way to greatly increase your bottom time.

 

[eelnoraa]

"Table is for square profile", this statement itself shows the lack of understanding of using table.

 

[Craig66]

"Table is for square profile", this statement itself shows the lack of understanding of using table.

Really????? Could you explain further???? Unless you are using a wheel the standard tables assume each dive is completed for the duration at max depth. Hence a square profile. Down. Max depth for duration then up. Square profile. Table does not give credit for multilevel diving. Open water divers do not go into the use of the wheel. That is generally reserved for AOW

Now let's hear why my understanding is lacking????




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[Centrals]

I can think of many dive operators where no computer means no dive. While it is NOT absolutely necessary but it does make your dive a bit more easier to manage.
Learn how to use the "wheel" if you do not want to use computer. BTW, a good bottom timer is not that much cheaper than a cheap computer.
Dive conservatively.

 

[Roman_66]

"Table is for square profile", this statement itself shows the lack of understanding of using table.

Maybe something has been changed from time when I did my course, but wikipedia still thinking that :

Decompression tables are drawn up based on the assumption that the diver will follow a square profile.

 

[Centrals]

.... In math classes, you probably learned how to calculate square roots by hand. Do you think the ability to do that by hand is a critical skill, or is it OK to use the calculator to find that for you?

It was NOT an option back in the mid 60's!!!
I still know how to calculate square root after all these years!