Another Tables vs. Computers Thread

[DivesWithTurtles]

Quoted from another thread:

Frankly, people keep going back and talking about the use of tables. Seriously, what is the difference between reading something off a table and reading it off a screen? If you don't know how the number was reached or what assumptions underlie the computation, it's a mechanical process. Learning to use the tables in OW was a mechanical process. We knew little or nothing of where those numbers came from -- even the people teaching us didn't know, which became apparent when I started asking awkward questions.

Ignoring issues of reliability, just considering understanding of decompression, why do so many people repeatedly say that learning to use the deco tables in OW is preferable to learning to use a computer?

 

[The Kraken]

Because the battery in a table never goes dead.

the K

 

[BHB ScubaTroll]

Ok, everyone has heard me defending other teaching methodologies... and I will continue to do so.

Here is what I believe.... Least common denominator for any situation.

When flying, with all the fancy equipment and with all the computers, it is REQUIRED to understand and complete the math by hand (with a basic slide rule for flying). Why? Least common denominator if equipment fails.....

I CHOOSE this ideology when diving as well. Do I use a computer, a redundancy, and a redundancy to the redundancy... Yes!, But, the tables are with me for EVERY SINGLE DIVE.

 

[DivesWithTurtles]

Because the battery in a table never goes dead.

the K

And lack of battieries help you understand deco theory how? Read the original question, K.

 

[speedhound]

I agree with the above. I dive with a computer (because it's easier), but I always do my tables and keep them with me as a back-up. The battery doesn't go dead in tables, and I like the crowd of other divers that gathers around me, murmuring things like" geesh, I had those somewhere", "so that's what those fancy coasters are really for", etc

Edit:
Just read the latest post. I learned to cover deco with tables in OW, because after using the tables for dive planning, it was a natural step to introduce deco while the tables were to hand. Also, and probably an important reason, is that most students don't have their own computer while going through OW class. If you learn using the tables, then you have a back-up to a computer.

 

[minnesota01r6]

The difference between flying and rec diving on nitrox is that when rec diving you can terminate a dive at any time as soon as your computer fails. If your avionics fail in a plane, you still need to find an airport and land (you need to know where you are, where the winds will push you, etc.) If a computer battery fails, you end the dive and don't get to dive for 24 hours unless you have kept track of your N2 & O2 apart from the computer. This is the only risk I see with solely using a computer. You ARE dependant on your computer, but for most divers with no deco obligation, it doesn't matter. Computer failure = ascend to 15 feet, safety stop, surface, don't dive for 24 hrs and get computer fixed. The theory behind nitrox is still taught, you just have a different means of obtaining the information.

 

[MikeFerrara]

Learning tables does a lot of things for you even though it doesn't make you a physiologist specializing in decompression.

Just a couple of examples...

Learning tables, especially if you really study them can leave you with enough in your head that you pretty much know what the computer is going to say before it says it. That's can be a very poerful advantage especially when the computer says something wrong and I've seen that happen lots of times. You might not need that advantage to save your life (although that has happened to) but it can sure save a dive or a day of diving and it certainly gives you more decision making power as apposed to just reacting to what a computer is telling you.

Looking at a veriety of tables is a good illustration of how much one can differ from another and the same goes for computers. Especially once you have some experience with various models or profiles you may very well find that there are computers (and tables) out there that you wouldn't want to dive.

As for learning a little about actual decompression theory, I'm all for it. Again, it makes you better able to decide for yourself which table or computers that you want to use and how.

 

[victor]

Quoted from another thread:

Ignoring issues of reliability, just considering understanding of decompression, why do so many people repeatedly say that learning to use the deco tables in OW is preferable to learning to use a computer?

I can only explain this from a personal point of view.
Knowing how to plug numbers into a formula and use a calculator does not mean that you understand the principles behind the calculation.
For me the biggest difference is the ready reckoner in my head. Before I run the numbers I know, roughly, how big or small the answer will be and what the level of accuracy I should expect.
By understanding the principles behind the calculation I know where errors are likely to appear. I understand why some numbers have to be to 5 decimal places while integers are accurate enough for others.
Very important, if the calculation results in an answer that is different from what I expect I know to STOP.
Maybe I did something wrong, maybe my reckoner was wrong, but I find out what is wrong before I continue.

 

[halocline]

The original poster clearly said "ignoring issues of reliability" yet so far all the responses are about equipment failure...well, at least you got the ignoring part!

Learning the tables gets a diver more involved with dive planning and understanding deco limits BEFORE a dive, not only when the computer starts beeping. Plus, the tables are non-linear to an extent, which can give a new diver an appreciation of how some depth/time changes are more critical than others. It's an active process to solve NDL and/or minimum surface interval problems with the tables, which at least gets divers thinking and comparing various dive scenarios. Now, you could certainly do the same thing with a computer in plan mode, and maybe best of all would be software that you could study previous dive profiles and input new ones while getting theoretical deco information about specific events during the dive profile.

For most rec divers, using a computer simply means looking at the display while diving and responding to deco problems that arise. This is a much more passive and reactive approach to deco theory in diving.

 

[captain]

Even with GPS and all the fancy electronics any sane mariner making an ocean crossing will have a sextant and all that goes with using it which also includes the knowledge of celestial navigation. It is also requried by the USGC for offshore licensed captains. I consider it the same with decompression. I use a computer but always have tables with me and the knowledge to use them.