Computers and "technical" diving

I have spent many hours thinking about why some members of the board are so anti-computer and some are pro-computer (with appropriate backup, of course). Finally the reasonings began to make sense. If someone is diving a "square" profile with an absolute bottom and very little depth variation (which it seems most of the anti-computer guys are doing), than a computer is a very ignorant tool to be using. A computer does nothing for you here that tables won't do.
The reason I am pro computer is because my typical profiles are nowhere near square. We have cave systems in Florida that have depth variations in excess of 100 feet. The profiles are very up and down. In this scenario, tables are very damaging as the hangs become very long very quickly. Planning a multi-level dive of this magnitude (with no knowledge of how the system depths vary) is not feasible.
For example, in a two hour dive at Ginnie, if you planned for max depth of say 100 feet but spend most of your time between 50-80, your hang would be quite lengthy. With a computer (using tables as redundancy in case of failure), your hang is cut significantly (and SAFELY). Throw in the deep stops that almost everyone advocates and you are good to go.
For the die hard computer haters, I understand why your profiles lend themselves so easily to disliking computers. I use tables on wrecks and have a computer for profiling/BT.
Sometimes you have to appreciate the value of a tool if used properly.
Cheers and safe diving

I actually do it backwards to most folks, I use a computer as a backup. Not a backup for lost tables but for a busted plan. An example would be the site being deeper, or shallower, than had been planned for. When the planning is right on I dive the tables generated by Deco Planner or Decoweenie.

I think its important, if one chooses to use a computer, that it be the proper computer for the job which, for tech diving, leaves only a couple options. Mine is a VR3. I hear DiveRite is going to release a mix computer soon based on their Nitek3 design. They're hoping to take VR3's market share by pricing much lower.

Tom

I agree with the point that wreckers and computers might not be the thing to do. I use only tables on wrecks but like to bend my computer sometimes. I have cut some special tables for places like Cow Springs to avoid a 30' stop, plus some other assumptions about the dive. I have a 32% mix table for ginnie that a 90 minute dive requires 39 minutes of deco. A table can be cut but it takes some knowledge of the cave and the tables you are using to do it. When using tables I just feel better and in control of the dive. Your right a computer is just a tool. If I use one I prefer to use it to supplement the puter tween the ears, not depend on it to get me out. Just my $.02

I don't understand your opposition to using a computer on wrecks. IMHO, wreck diving is ideally suited to the advantages of computers.

What is causing you to do 39 min of deco at Devils on 32%? Is that without o2 deco? If you run 32-33 up to 100min at Devils you should require no longer than 20-24min max deco time.

On cow...why would you suggest cutting tables to avoid a 30ft stop (inside the restriction I guess?). Seems to me to be part of the overall safe ascent and there really is no way to 'make up' shallower for blowing off a deeper stop....but there is the possibility of blowing off or shortening shallower stops after doing or lengthening the deeper ones. Old habits and teaching of 'getting out of deep water fast' are hard to break- thank your original ow instructor and agency.

True the knowledge is requisite, hence the value of standard mixes. That way you 'learn' the deco and not simply memorize the tables for a particular depth and time component.

For example- I recently returned from Scapa Flow in the north of Scotland. I did not take a computer not even for the 'recreational depth' dives which most of them were. Merely requested and ran with the mixes/deco that I was used to (many of the profiles approached those that I had run in places like Devil's or lower peacock etc). No cutting tables, no recalcing for contingencies, no altering computer settings between diving.....pure computational freedom and the freedom from having to bring computer, laptop, or pda along. I was free to concentrate on the diving.

Waterlover once bubbled...
I have cut some special tables for places like Cow Springs to avoid a 30' stop, plus some other assumptions about the dive. I have a 32% mix table for ginnie that a 90 minute dive requires 39 minutes of deco. A table can be cut but it takes some knowledge of the cave and the tables you are using to do it. When using tables I just feel better and in control of the dive.

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Walter once bubbled...
I don't understand your opposition to using a computer on wrecks. IMHO, wreck diving is ideally suited to the advantages of computers.

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At first this seems quite logical. Upon further inspection, what happens if your computer fails...what then? You will say to just ascend....Ok...to where..what depth and why? 15ft 20ft 30ft? What happens if it craps out when you have a manditory deco ceiling or malfunctions? The key to the arguements surrounding the nonreliance on computers as 'computational devices' are pretty simple. If any piece of equipment fails, you want to minimize the effect of the failure..right? Well if your computer fails you lose your bottom timer and your ascent indicator (deco obligation or nostop time). Would you not benefit from securing this info in your own brain that if it fails...then you have a much bigger problem than the deco ceiling above you.

Your buddy has a computer right? Great that's your back up....or did he really have the same profile and is it the same computer and settings as yours with the same repetitive dive info? If you used your 'grey matter tables' you merely use his depth indicator and timer and have him accompany you throughout the most 'conservative' of the two ascents either of you would be required to do.

Hey Waterlover,
Do you actually use this profile at Ginnie? Typically, a 90 minute dive in Ginnie will net maybe 17 minutes (O2) plus the stop at the rock at 40 for a few and then in the bowl at the eye for a few. We do this dive a few times a week, give or take a few minutes (or an hour). I am thankful for the additional tool on dives like these.

I've done several dives in Cow as well. Where are you going in Cow to mandate doing deco in a restriction?
We do stops in the hole in the ceiling prior to the second restriction "Sandy", and avoid this spot all together.

Thanks for the input as I enjoy learning from others.

Cheers

Hey Mad,
Where did you get the devil? That's funny!

Those arguments are not wreck specific, they apply to any dive.

For a back up, I use my other computer.

Divesherpa once bubbled...
Hey Mad,
Where did you get the devil? That's funny!

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He was just waiting there and somehow he seemed appropriate- although I'll have you know he's a 'DecoWeenie'.