Backup to integrated computer

[Slater]

Last November experienced a airpressure reading failure on my Suunto Cobra, just a year old.
Was a night drift dive, had 3500psi on the surface..
Rolled in & got to the bottom & computer tank psi reading was blank....
Was a fast drift & made the dm aware of the situation as we continued along, I stayed close.
About 30-40 minutes in I started sharing his air on the long hose just as a precaution, did a safety stop on my air & ended the dive.
We knew it was just a AI reading failure & it was just that one dive where I encountered the problem.
After we surfaced the dm ran an additional spg as a safety measure but read correctly after that but continued to run the spg the entire trip.
Sent it to Suunto when I got back to check things out, they looked & tweaked, returned it to me & so far so good.
Suunto never really found anything solid but did an update & some cleaning / replacing a component just as a precaution.
Staying streamline & drama / hassle free is #1 for me & contemplating making a change but lots to consider.
A bungeed computer on wrist & then a compass on other wrist, sounds like drama but love the idea of getting rid of the console???
Keeping the Suunto Cobra / compass combo & adding my own Spg so I dont have to deal with a compass on my other wrist?
Then just using an additional wrist computer as a back-up.
Just one part of me thinks would be nice to get rid of the computer AI hose all togther but then again to avoid the need to abort a dive I should have a analog spg so ill have that hose regardless...

 

[BabyDuck]

if you're doing a dive that's simple & common for you (your local quarry, say, or your local beach, or whatever) and losing your computer would just mean the dive's over, i wouldn't carry a backup. i really do think you need one on a liveaboard or week long dive vacation though.

i just have two wrist computers, but if a console computer is your thing, that's cool. (i do take both every dive, because i do some deco diving & need a backup for that, but it is overkill for a simple common dive.)

 

[diverrex]

if you're doing a dive that's simple & common for you (your local quarry, say, or your local beach, or whatever) and losing your computer would just mean the dive's over, i wouldn't carry a backup. i really do think you need one on a liveaboard or week long dive vacation though.

i just have two wrist computers, but if a console computer is your thing, that's cool. (i do take both every dive, because i do some deco diving & need a backup for that, but it is overkill for a simple common dive.)

Your buddy might not think it's overkill for you to carry a backup so you don't have to abort his dive when your computer goes out.

 

[altaskier]

Similar but not exactly what gizmo said, my wife uses a Cobra 3 and a Zoop as a backup. She takes the Zoop on every dive. If the Cobra 3 were to fail, she would immediately ascend, and then on the SI switch out the Cobra 3 hose for a hose with a small SPG on the end, and resume diving using the Zoop. She sees no reason to keep the SPG and hose attached so long as the Cobra 3 is working fine--it would just add clutter in view of the low likelihood of failure.

My approach exactly.

 

[BabyDuck]

Your buddy might not think it's overkill for you to carry a backup so you don't have to abort his dive when your computer goes out.

and i do, but the point was if it's just a regular everyday dive in your usual spot, ending a dive isn't the end of the world.

 

[DevonDiver]

For recreational diving, I don't see much point in computer redundancy. The surface is always an immediate option, so there is no safety context to the redundancy, providing the diver is properly trained and competent.

That leaves the choice to make a $$$ investment to save a subsequent dive/s on the same day, in the extremely rare event that a computer fails significantly into the bottom time of the first multi-level dive of a day series. Subsequent days diving could be managed on RDP (which assume clear well within 24 hours anyway...). In many cases, the failed dive could be assimilated into a square profile table dive anyway, and more likely still into a multi-level profile (wheel, eRDP, laptop/smartphone planner etc ...).

Unless diving solo, your buddy should be able to provide you with a fairly representative profile for subsequent conversion to tables/multi-level. Assuming, of course, you dived with some buddy-team discipline.

Hundreds of dollars investment to insure against the very rare chance of losing tens of dollars of dives seems a little absurd...?!?

 

[diverrex]

For recreational diving, I don't see much point in computer redundancy. The surface is always an immediate option, so there is no safety context to the redundancy, providing the diver is properly trained and competent.

That leaves the choice to make a $$$ investment to save a subsequent dive/s on the same day, in the extremely rare event that a computer fails significantly into the bottom time of the first multi-level dive of a day series. Subsequent days diving could be managed on RDP (which assume clear well within 24 hours anyway...). In many cases, the failed dive could be assimilated into a square profile table dive anyway, and more likely still into a multi-level profile (wheel, eRDP, laptop/smartphone planner etc ...).

Unless diving solo, your buddy should be able to provide you with a fairly representative profile for subsequent conversion to tables/multi-level. Assuming, of course, you dived with some buddy-team discipline.

Hundreds of dollars investment to insure against the very rare chance of losing tens of dollars of dives seems a little absurd...?!?

I think the risk reward ratio needs to be determined by how often and where one dives. A casual recreational diver making a few dives year probably won't benefit much from the redundancy. But someone diving several times a month and taking one or two dive trips a year easily could. In SoCal our local day trips average $130 to our closer islands and up to $180 a day for further out trips. Two-day trips run around $350. I'm only a semi-regular diver making 1-2 local trips a month but even at that rate I spend a couple thousand each year on local trips. A $300 extra dive computer that can easily last 5 years seems like a reasonable investment to me to keep a dive day going smoothly. And if you are making fairly expensive dive trips once or twice a year the extra protection of second computer is even of more benefit.

My primary computer has never died on me but I have lent out my backup computer to a dive buddy on 3 occasions.

 

[dmoore19]

I think the person spending $5000-10000 on a dive trip can justify a $300 backup computer. If you spend that much money and lose even 1 dive the investment is worth it.

 

[TotDoc]

For recreational diving, I don't see much point in computer redundancy. The surface is always an immediate option, so there is no safety context to the redundancy, providing the diver is properly trained and competent.
...
Hundreds of dollars investment to insure against the very rare chance of losing tens of dollars of dives seems a little absurd...?!?

Except for a traveling recreational diver, then. If I make vacation plans that revolve around diving - which is what I typically do - losing out on a day of diving is losing out on a day of my vacation. That's not a chance I am willing to take.

 

[Colliam7]

Staying streamline & drama / hassle free is #1 for me & contemplating making a change but lots to consider. A bungeed computer on wrist & then a compass on other wrist, sounds like drama but love the idea of getting rid of the console??? Keeping the Suunto Cobra / compass combo & adding my own Spg so I dont have to deal with a compass on my other wrist? Then just using an additional wrist computer as a back-up. ust one part of me thinks would be nice to get rid of the computer AI hose all togther but then again to avoid the need to abort a dive I should have a analog spg so ill have that hose regardless...

If I read your post correctly, it seems that the actual issue you encountered was loss of gas information. I didn't see you comment on concerns about loss of depth or time data.

There are several schools of thought, and multiple threads, on the AI (wireless or hosed) vs SPG issue. It is a personal preference thing, so take my comments as just that - my personal preference.

A general comment to begin: I don't care for consoles, and although I will dive them if that is all that I have available, I prefer wrist mounted depth and time gauge information.

For me, gas supply awareness is key, which is why I always have a SPG (that is not to say I will never have one fail underwater, just that I haven't had that happen yet). Put another way, I never dive without a SPG. If my SPG fails, the dive is over. That has never happened to me.

I frequently dive with a wireless AI computer (wrist-mounted), in addition to my SPG. I do not think it is possible to discern any material effect on 'streamlining' associated with a second HP hose. I like the convenience of simply rotating my wrist to check pressure, depth, and time simultaneously. The AI function periodically loses sync. I can usually count on that happening at least once during every dive. It (almost) always reestablishes sync during the dive.

I frequently dive with a second computer, even in the quarry (as much out of habit, and a desire for consistency, as need).

For recreational dives:

a) If my computer AI function fails - I lose pressure data on my wrist - nothing changes. The dive continues as before.
b) If the computer altogether fails - no time, no depth, no pressure - and I have a back-up computer, nothing changes. The dive continues as before.
c) If the computer altogether fails - no time, no depth, no pressure - and I do not have a back-up, and I am diving with a buddy, I rely on my buddy for time and depth. The dive continues.
d) If the computer altogether fails - no time, no depth, no pressure - and I do not have a back-up, and I do not have a buddy, I end the dive with a normal ascent (open ocean), or I end the dive with a swim toward the entrance (quarry).

Given my stated personal preferences, it is probably not surprising that I endorse two of the options you listed: 'A bungeed computer on wrist & then a compass on other wrist, sounds like drama but love the idea of getting rid of the console", and 'have a analog spg so ill have that hose regardless' and