why analog?

[TomP]

Scuberd,
If you plan to go DIR or even text book Hog then get the SPG.

Otherwise...
The only valid arguement i've seen in this thread is relative to size, and the problem that may pose with stage bottles. One decidely un-DIR solution, and I know I'm going to regret this, is to route it differently. I route my SPG under my left arm [beneath the harness] and under the waistband just to the right of my crotch strap. It is in the way of nothing and can be read without being retrieved to do so.

 

[Cheekymonkey]

Thats interesesting under the harness.

 

[grazie42]

It´s not that you can´t use the cobra as an spg (though I do agree with the size and failiure arguments), it´s just that I think you´d be better served by exchanging it for an analog spg and simple BT. "Dive" your Vyper for your recdiving (if you want) and you´re all set.

ymmv

 

[TomP]

It´s not that you can´t use the cobra as an spg (though I do agree with the size and failiure arguments), it´s just that I think you´d be better served by exchanging it for an analog spg and simple BT. "Dive" your Vyper for your recdiving (if you want) and you´re all set.

ymmv

I'm still not sure I understand exactly what the failure arguement is. I could just as easily argue that a bottom timer combines the features of a dive watch and depth gauge and simply assert that its more prone to failure than either.

 

[limeyx]

I'm still not sure I understand exactly what the failure arguement is. I could just as easily argue that a bottom timer combines the features of a dive watch and depth gauge and simply assert that its more prone to failure than either.

You could, but at some point you have to have some kind of a balance.
Some people take two BT's (but what do you then do if they start to disagree with each other?)

I know that if my BT fails, my buddy has a perfectly good working one (unless we are really having a bad day!) So we exit the dive and I simply match their depth.

I also know that my buddy/team has enough gas to get us out of the dive if one of us goes OOA, so worst case if my SPG craps out, we end the dive and have plenty of gas.

Plus, I should know what my SPG ought to read before I look at it.

 

[TxHockeyGuy]

I am decidedly not tech, but thought I'd share my list of failure experiences. I have personally had my analog depth gauge fail by reading 10 ft shallow. I was diving a familiar area and knew what my depth should be so I was really surprised to see what it told me, I also double checked it against my computer which confirmed my suspicion. I've also been on a dive with a buddy where his air integrated (non-wireless like the cobra) computer completely failed at depth, he had no psi or depth at this point. It wasn't a huge deal since we had both been keeping track of each others air and knew his air consumption to be better than mine, we continued the dive albeit more conservatively. So from my admittedly very limited experience I've seen both digital and analog failures (albeit not a spg).

While my configuration as I have said is decided non tech, I now dive with an analog spg, an air integrated wireless computer on my wrist, and a second non air integrated computer on a retractor. I'd have to have 2 failures to lose either psi or depth with this configuration.

 

[jeffrey-c]

....Some people take two BT's (but what do you then do if they start to disagree with each other?)

"A man with a watch knows what time it is. A man with two watches is never sure."
-- Segal's Law

 

[limeyx]

"A man with a watch knows what time it is. A man with two watches is never sure."
-- Segal's Law

And a man with three watches needs long arms

 

[TomP]

You could, but at some point you have to have some kind of a balance.

Agree, so what about the Cobra is out of balance? Remember, from a computer/BT perspective it would be a backup.

Some people take two BT's (but what do you then do if they start to disagree with each other?)

I assume you mean out of whack in a way that goes well beyond differences in body placement. This is a good thing because it alerts you to a malfunction. Cross check with your buddy to see which one is failing. If I was solo i'd follow whichever reflected the greater N2 exposure.

I know that if my BT fails, my buddy has a perfectly good working one (unless we are really having a bad day!) So we exit the dive and I simply match their depth.

I also know that my buddy/team has enough gas to get us out of the dive if one of us goes OOA, so worst case if my SPG craps out, we end the dive and have plenty of gas.

Again, my point was about the liklihood of the failure and not the response since it's a given that you'd thumb the dive if your spg - analog or AI - failed.

Plus, I should know what my SPG ought to read before I look at it.

Agree completely

 

[limeyx]

Agree, so what about the Cobra is out of balance? Remember, from a computer/BT perspective it would be a backup.

I assume you mean out of whack in a way that goes well beyond differences in body placement. This is a good thing because it alerts you to a malfunction. Cross check with your buddy to see which one is failing. If I was solo i'd follow whichever reflected the greater N2 exposure.


Again, my point was about the liklihood of the failure and not the response since it's a given that you'd thumb the dive if your spg - analog or AI - failed.


Agree completely

All I can say is that it is about a small-enough set of gear that gives you enough reliability, enough redundancy (including that from your buddy), and one that a big enough group of people can reasonably agree on.

If it's a backup -- is it really needed? What if it failed? Could it cause gas to leak out? (These are somewhat hypothetical questions obviously, and could apply to multiple kinds of gear).

Ultimately, DIR chose to use an analog SPG because they are generally reliable, sturdy (wont get their faces smashed/scratched too much when they get bashed by stage bottles), consistent (no having a digital gauge on one tank and analog on the other), etc. and they set a standard.

Also, the standard is for one depth-keeping device and one (water-activated?) time keeping device (which do not necessarily have to be the same, or digital I guess).

This means that I can show up for a dive with DIR buddies and know we have (to a reasonably approximation) very very similar gear. If my SPG goes south, I am 90% sure that I can borrow one that will look familiar to me (sadly not the case with a lot of Bottom timers still).

And finally, I'm a software engineer that works on projects involving software controlling hardware. How a lot of this stuff gets developed scares me.

Also, water and electronics dont tend to mix well.

Two SPG's (in my opinion) on the same tank is overkill. Two BT's -- well, it depends on the dive I guess. For recreational or "shallow" tech dive, not necessary.

for a 14 hour runtime cave penetration dive? Maybe you need more redundancy.

"Dont take what you dont need"