Necessity of a back up computer/watch for NDL diving

[Joneill]

That's the logic problem: the impact is exactly the same after 1 dive or 4 days of 4 dives. You don't know your exact residual loading, but you know the upper limit on it: you're at most in pressure group Z.

And because I wear a backup DC, I don't have to guess about residual loading or assume a worst case pressure group and needlessly limit myself- regardless of the frequency/length/depth of diving prior to the failure. As I said, for me, a backup computer is a no brainer.

 

[jale]

Hi
rant
It seems there are a lot of confusion between modern equipment and safety, between precision and accuracy.
If you want to talk about safety you don't dive 4 times a day for a week. Full stop.
And then, no, you don't need a second DC.
And even for "basic rec scuba dives" (and 4 dives a day can only be basic rec scuba dives, right?) do you really need a primary DC?
Yes DC is convenient but do you know what and how it calculates?
10 minutes reading about basic decompresion goes further than 30 minutes trying to make sense of a DC manual.
Make me shake my head the divers feeling so safe because they can flash a SW or two!

 

[MaxBottomtime]

And people used to use these as primary transportation too:

View attachment 510607

It's 2019 - why live in the past when there are solutions that add convenience and enhance safety versus what was used in the past!

Horse and buggy-car is a lot different than DC-depth gauge. I can make the same dives using a depth gauge as I can a computer. Also, I'm not advocating not using a computer. I'm only saying a backup is not a necessity.

 

[caruso]

Horse and buggy-car is a lot different than DC-depth gauge.

It's called an analogy.

 

[penak]

I vote : "Yes, second dive computer"

 

[Joneill]

Hi
rant
It seems there are a lot of confusion between modern equipment and safety, between precision and accuracy.
If you want to talk about safety you don't dive 4 times a day for a week. Full stop.

Who said they were doing 4 dives a day for a week? Regardless, 4 dives a day even for a week is not necessarily unsafe - people do it on live-aboards all the time! It depends on lots of factors including depth, time, diver's physical fitness, exertion, etc., etc.,. That's the beauty of modern dive computers: they can provide you with information that can keep you safe over multiple dives over multiple days if set up properly.

And then, no, you don't need a second DC.

You don't "need" many things we dive with - but a second DC can be beneficial if your primary fails. "Full stop".

And even for "basic rec scuba dives" (and 4 dives a day can only be basic rec scuba dives, right?) do you really need a primary DC?

Not sure what you mean by the first part but, where I usually dive, no DC means no diving - It's mandatory!

Yes DC is convenient but do you know what and how it calculates?

Yes, I do.

10 minutes reading about basic decompresion goes further than 30 minutes trying to make sense of a DC manual.

Maybe for you...

Make me shake my head the divers feeling so safe because they can flash a SW or two!

Silly comment and no one was talking about wearing two computers to flash them around. Thanks for the useless add/veiled insult. Makes me shake my head when folks post comments like that!

 

[Joneill]

Horse and buggy-car is a lot different than DC-depth gauge. I can make the same dives using a depth gauge as I can a computer. Also, I'm not advocating not using a computer. I'm only saying a backup is not a necessity.

Not different at all as it is also just an evolution of technology - you can get from point A to point B with the horse and buggy just like you can with a car - just not as conveniently or safely.

I also never said a backup computer is a necessity. I've merely provided perspectives on where it is is beneficial and why I carry one. Since you are obviously against a back up computer, how about providing us with some good reasons as to why a backup DC is a bad idea or creates issues? That way people can weigh both sides and make their own decision!

 

[tursiops]

I can make the same dives using a depth gauge as I can a computer

Only true if you are doing square profiles or really trivial multi-level dives.
Perhaps YOU are doing square profiles. Fine. Few do.

 

[MaxBottomtime]

Not different at all as it is also just an evolvement of technology - you can get from point A to point B with the horse and buggy just like you can with a car - just not as conveniently or safely.

I also never said a backup computer is a necessity. I've merely provided perspectives on where it is is beneficial and why I carry one. Since you are obviously against a back up computer, how about providing us with some good reasons as to why a backup DC is a bad idea or creates issues? That way people can weigh both sides and make their own decision!

I never said it was a bad idea. I said it was not a necessity.

 

[caruso]

10 minutes reading about basic decompresion goes further than 30 minutes trying to make sense of a DC manual.

I don't have any problems "making sense of a dive computer". I have read every page of my dive computer manual and I understand each function literally like the back of my hand and I find that information at least as important as "basic decompression" which I haven't read about since my early days of Open Water training.

Make me shake my head the divers feeling so safe because they can flash a SW or two!

You shake your head because divers flash a SW or two? What does that even mean and does your head hurt after a while from all that shaking?