Computers & DIR

[fishb0y]

So I'm reading the DIR Fundamentals book, and I have a few questions/comments regarding the dis-approval of computers when "Doing It Right. My class is still 4 months away, but I like to be prepared. For those of you at home, please follow along in your book (page 107).

I was going to go over each of the Baker's Dozen, but after re-reading this a dozen times, all the points seem to direct to the same argument that computers are too inflexable.

My 10 years of diving has always told me the opposite. Granted, I have not used computer generated tables very often, but in my experience, the implied conservatism of a computer is alway much more flexible than tables.

I whole-heartedly agree that there is a relience on computers, expecially among long time computer divers, but how would diving a digital bottom timer be any different than diving a wrist mounted, non-air integrated computer?

 

[WaterDawg]

but how would diving a digital bottom timer be any different than diving a wrist mounted, non-air integrated computer?

A BT just gives you info such as time, depth, acsend rate, temp. So you dont really get any deco stuff like NDT remaining or whatever. So thats the difference. It only gives you info you could otherwise get from a watch and mechanical depth guage.

 

[Rick Inman]

Computer say go down. Me go down.

Computer say go up. Me go up.

 

[fishb0y]

A BT just gives you info such as time, depth, acsend rate, temp. So you dont really get any deco stuff like NDT remaining or whatever. So thats the difference. It only gives you info you could otherwise get from a watch and mechanical depth guage.

Guess I should have clarified myself... The DIR book says that a digital bottom timer would work great, but if reliability is a consideration, wouldn't a digit BT suffer some of the same fates as a computer? Why not add the NDT just for a back-up? I'm not trying to turn this into another bash DIR thread, but it just doesn't seem right saying computers have no place in diving. It's not like the diving industry is making Bend-o-matics anymore.

 

[fishb0y]

Computer say go down. Me go down.

Computer say go up. Me go up.

Honestly, how many non-instructors with over 100 dives do you know that dive computers, but can still work a set of tables. Deco tables are becoming a lost art... and this coming from a former SDI instructor. But I also believe that physics equations are alot easier with a calculator... Plan your dive, dive your plan.

 

[boomx5]

Guess I should have clarified myself... The DIR book says that a digital bottom timer would work great, but if reliability is a consideration, wouldn't a digit BT suffer some of the same fates as a computer?

I agree with you here. An electronic devise is still an electronic device regardless if it only calculates depth & time or your keeps track of and calculates your NDL's. I've had bottom timers fail on dives before and it's kind of a bummer.

For me, a computer is not as flexible and won't produce the proper deco schedules and would penalize me for some of our profiles as would software generated tables. The other thing is that if I lose my bottom timer during a dive, I always carry a backup just in case, instead of carrying another $1,000 electronic devise that could fail.

 

[fishb0y]

For me, a computer is not as flexible and won't produce the proper deco schedules and would penalize me for some of our profiles as would software generated tables.

What kind of software do you use, and what about multi-level diving?

 

[Soggy]

What kind of software do you use, and what about multi-level diving?

Personally, I use a printed out set of air tables combined with depth averaging. If I spend 10 minutes at 100 ft and 10 minutes at 80 ft, I just did 20 minutes at 90 ft. For deco diving, I use the same tables, but verify my dive with Vplanner prior to the dive. 9/10 times the profiles are near-identical. The other 1/10 times, the profile differences are so minimal as to make no difference in deco time.

From a set of air tables, you can extrapolate 32%, 30/30, 21/35, 18/45, etc etc based on EAD.

 

[wedivebc]

From a set of air tables, you can extrapolate 32%, 30/30, 21/35, 18/45, etc etc based on EAD.

What formula do you use to extrapolate heluim mixtures (EAD) ?

 

[Randy43068]

What formula do you use to extrapolate heluim mixtures (EAD) ?

the bendover rule. Bend over and kiss your arse goodby..