Sharing a dive computer....

[GrumpyOldGuy]

Since I am new to this and safety is a big issue, I though my wife and I could do this but saving money to buy just 1 computer for both does not worth it my life does not cost 300 usd. We already bought regulators and we are waiting til next month to buy our computers...

Good move! When my boys started diving, they saved up for their primary gear but could not afford computers. I sprang for 2 (ouch!) even though in our tight dive formation we could have shared. The first time they signaled me to slow my ascent and do a deep stop because they were monitoring their own DC (and I was spacing a bit and exceeded 30FPM), I knew it was a wise investment.....

 

[Max Speed]

In response to a few statements:

I never said I conducted an experiment. This was just something we noticed while running identical algorithms.

I never suggested anything about saving money. Surprisingly, to notice the identical computer readings we... Needed to own two computers. (duh!)

Anytime we jump into the water we already know exactly what the tables indicate for the planned dive. If it is a demanding dive we know what the tables say, what V-Planner says, and what the planning function on the computers say. If there is no hard bottom or there is uncertainty, we know the same answers for contingency depths.

Read carefully...e

 

[aquaregia]

Since I am new to this and safety is a big issue, I though my wife and I could do this but saving money to buy just 1 computer for both does not worth it my life does not cost 300 usd. We already bought regulators and we are waiting til next month to buy our computers...

I hope you have good tires on your car.

 

[Max Speed]

Are you suggesting that if one of the computer fails under water you and your wife could rely on the other computer for the remaining of the dive?

Yes, I am suggesting that. I would abort immediately if it was down to a few minutes of no-deco time but if there were a dozen or more minutes left I would be comfortable leaving the water at a more leisurely pace. (Assuming a recreational profile.)

 

[GrumpyOldGuy]

Yes, I am suggesting that. I would abort immediately if it was down to a few minutes of no-deco time but if there were a dozen or more minutes left I would be comfortable leaving the water at a more leisurely pace. (Assuming a recreational profile.)

I would concur. I actually do record NDL on identical computers for myself and my sons, it is always close enough. For me, the no-sharing rule if more of a mental state of preparedness rather than a functional difference (at least in NDL / rec dives).

 

[Centrals]

Yes, I am suggesting that. I would abort immediately if it was down to a few minutes of no-deco time but if there were a dozen or more minutes left I would be comfortable leaving the water at a more leisurely pace. (Assuming a recreational profile.)

I would ascend to 9m with my buddy and stay there for couple of mins before taking another 5mins stop at 5-6m. No diving for the next 24hrs.
Quite a common sight to see divers with two computers or an extra timer/diving watch.

 

[TSandM]

If one's computer fails while showing significant no deco time, it's good to remember how decompression theory works. Time at depth loads fast compartments, and they tolerate significant overpressure gradients. Time in the shallows loads slow compartments, and many of them aren't even relevant on recreational dives. If your computer fails at depth, proceed to shallow water expeditiously (30 to 60 fpm) and then stay there. I'd slow my ascent at half maximal depth, and spend as much time as I wanted in 30 feet or less. Figuring out what to do for the NEXT dive is a bit trickier.

 

[GrumpyOldGuy]

I would ascend to 9m with my buddy and stay there for couple of mins before taking another 5mins stop at 5-6m. No diving for the next 24hrs.
Quite a common sight to see divers with two computers or an extra timer/diving watch.

Yeah, I am one of those guys who wears 2 computers on a dive trip, but the sole reason is just to avoid having to stand out dives on a trip and/or back tracking to tables.

It still remains though that if I am with a buddy and my computer takes a dump I have options depending on how aggressive the dive plan is and if the subject of gear failure has been discussed with the buddy. I guess I still see a computer as a helpful gadgets, not critical.

 

[Airleron]

Think back to the early days of diving. Technically you can grab a cylinder of gas, hook up a regulator, don mask and fins, jump in the water and go for it. I think we'll all agree that over time we've learned that's not the best idea in the world. There's a lot of training and technique today to keep us alive. But, technically, it can be done.

Small Hijack: I respectfully disagree. It's the only way I dive now (oh I do use a spg). And I'm technically a better diver for it because you must hone skills to dive sans BC, etc. I agree it's not for 97% of the divers out there though.

Carry on.....

 

[Levigarrett]

No particular point. Just interesting in that if you computer fizzles, and you're not running a spare or logging tables and you stick to your partner like glue, your diving day can continue. So I would put the commonly heard statement that you cannot share a computer into the same catagory as split fins will kill you. Both statements have a sound basis but they are not universal truths. Now if you go below 130'...

What's below 130?