DIR & computers

[caveseeker7]

This is a question to you DIR divers.

Why doesn't DIR condone the use of them ?

Don't tear me up guys, I'm just trying to understand. It just doesn't (yet) make any sense to me. Bottom timer/depth gauges (battery powered) are used, so battery failure isn't the reason. Computers (PC/PDA) are used with deco software to calculate dive profiles, mixes, deco etc. . Yet a dive computer doing the same on the fly is not used. But the fact that it's a computer generated computation can't be it, either. Not even those that have algorithms by people that write the deco software (Explorer/VR3) ? As they are from the same people, the software is not at fault.

So, why aren't dive computers used by DIR divers ?

Addited : This is not ment to become a dicussion who's right or wrong, so please, for once, don't.

 

[jonnythan]

http://www.scubaboard.com/showthread.php?s=&threadid=27676&highlight=dir+computers

 

[boomx5]

There has been alot of good info posted here on that subject. If you do a search, you should find all the answers you need as well some that you don't. On a side note, does anybody find it disturbing that when someone asks a simple DIR related question, they have to worry about getting yelled at?

 

[jonnythan]

boomx5 once bubbled...
There has been alot of good info posted here on that subject. If you do a search, you should find all the answers you need as well some that you don't. On a side note, does anybody find it disturbing that when someone asks a simple DIR related question, they have to worry about getting yelled at?

*I've* noticed that nobody ever yells at anybody, and I always wonder why people put that kind of disclaimer on things. It's silly.

 

[vicky]

I don't know (almost) anything about DIR, and why they don't like to use computers, but a possible reason why one would not rely on a computer is that a computer, in some way, contradicts the "plan your dive, dive your plan".
What do I mean? A diving computer will allow you to do anything. If you stay a few more minutes in 40meters and as a consequence get into NDL, it will tell you "OK, you're out of NDL, please go up to X-meters for your first deco stop". Suppose you ignore it and keep staying at 40 meters for several more minutes, it will recalculate your deco stops and tell you the "new stops program". It will keep that way untill you really ignore deco stops and most computers will lock up displaying some sort of "Error" on their screen.
Well, I made an out-of-NDL dive, what's wrong with the computer telling me where to stop, one may ask himself... Suppose the way you extended your dive made the computer calculate a 10min stop at 9m, 15min stop at 6m and, say, 29min stop at 3m.. Do you have with you all the air needed for such deco stops? Did you plan to do them in advance? Did you take all the needed air in advance? And what if the computer calculated for you 2 hours of deco stops? What are you going to do?
If you planned your dive in advance you'll know how long the dive will be, take enough bottles (with accurate mixes) with you or change the plan if it is exagerated, add several bailout options, perhaps have a support diver in standby with more air, etc.
IMHO if one wants to do an accurate diving plan he doesn't need to rely on a computer, he can plan everything on advance.

For a recreational diver, like me, a computer is excellent. I don't really plan an accurate diving, minute to minute, meter to meter. I know the site, maximum depth etc. and when I get to just about 3-4 minutes from NDL I start ascending slowly on the reef, and if I suddenly see a whale shark on the way and and the computer "allows me", I'll stay a couple minutes more to take a photo, and so on. That's a multilevel dive, and for a recreational diver most dives are like these.

 

[GeekDiver]

I'm not DIR nor specificly headed that direction but I am looking at getting into extended range diving.

I don't think the DIR folks are so much oposed to them. It's that most computers wont do the job for deco diving. Alot of the DIR folk will at least admit to owning a viper or stinger but they use them in guage mode because the computer would be wrong if they dive with more than one mix. This is one reason why atl east. Most computers can't perform multiple gas switchs which affect the deco time and the SI. The cave or deep diving folks are diving multiple mixs to help accelerate deco. I was looking into the dives for the Padi/Dsat tec class and they make 12 dives using 21% to as much as 60% o2 depending on the profile of the dive. one gas may be used for travel gas then another gas for deeper stops then a highe gas for shallow stops. Since there are few computer that can handle 3 differant gas mixes then you couldn't use most computer to account for the changes. Since you shouldn't casualy make deco dives they should be well planed and the plan should be followed. If you have a plan and follow it then you don't need the computer in the first place only a depth guage, SPG and BT to make sure you follow the plan as profiled.

 

[caveseeker7]

I figured the answer is somewhere, but there are a lot of posts here.

boomx5 once bubbled...
On a side note, does anybody find it disturbing that when someone asks a simple DIR related question, they have to worry about getting yelled at?

Past experience, though not for asking a question on this board (it was the 1st of its kind for me). There is an aweful lot of good stuff in the DIR system, though due to the all or nothing aproach I'll probably will never DIR ...

Anyway, thanks for your posts.
Stefan