Backup Computer?

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ttriton

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Location
Louisiana
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My main computer is a Uwatec Smart Com, I was thinking of getting a non ai, wrist computer and a spg for a backup. Does the backup need to be in the same brand as your main or does it really matter. Mainly would want it to continue a diving trip, if main computer malfunctions. I was thinking I could dive with both, and if theres a problem with main, continue with wrist backup.
 
Of course it doesn't have to be the same brand if it's a backup, as long as it's reliable and functions properly and you know how to use it.
 
I'm tagging along on this thread since my question is a basically the same. I'm currently diving with a Vytec DS and was looking to buy a backup non AI computer. Does it matter to have the same algorithim? I was looking at the D4 since it is a Suunto product as well, but also liked the Geo 2.0 for its more reasonable cost and user replaceable battery. I also noticed the GEO 2.0 has the option for setting 2 profiles depending if you wanted to be more or less conservative. Any thoughts? I'm leaning towards the Geo at the moment.

Thanks!
 
I picked up a well used Zeagle Status I to backup my Oceanic ProPlus II on multiday trips. I think the main concern with the backup is that it be less conservative than the main computer. If you bend the backup and it goes into lockout mode or gauge mode then you haven't got a useable backup anymore. I like the Zeagle because it doesn't lockout under any conditions.
 
If you use two computers with very different algorithms and they would have different NDL/Deco time numbers, you'll either be violating the limits for one of them if you go with the more liberal computer. It is perhaps no big deal but something to think about.

What I am doing now is using two different models of the same brand, D9 with Stinger or Stinger with Cobra.

I like one of the two to be a watch type for me to forget about taking my watch if I am traveling away from home. One less thing to worry about losing.
 
why would you dive with computers with different algorithms? does not make sense to me. choose (a computer with) an algorithm that you trust and then get a backup which runs the same (algorithm).

running a conservative algorithm (=good!) and only in a violation scenario trusting a more liberal model defies logic, imho.
 
I've opted to dive with a back-up bottom timer/depth guage. In the extremely unlikely event that my computer dies while on a dive trip, I'll simply dive tables the rest of the trip if I can't rent/borrow another computer. Don't see the need to lay out the money for an additional computer when I can fall back on my brain.
 
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I use an Oceanic and it has a pretty liberal algorithm. To take this into account and stay conservative I use an OMS bottom timer and tables as back when using the computer. Course most of my diving is the other way around. I plan and dive a profile using tables and the computer is my back up. It's usually in gauge mode anyway. I don't even recommend computers to my students. If they want one I'll help them with it and cover computers in my classes but teach that they should be used as back up for the brain by new divers.

My own experience and that of many I talk to is that new divers (again myself included) will get (or got) a computer and shut their brain off. Use the computer and dive it right up to where it is still in the green or maybe a hair into the yellow and think it's perfectly safe.

And it may be, right up until you dive dehydrated, after a strenuous bit of exercise, just getting over a cold or hangover, and/or find out your tolerance to DCS is lower than the algorithm the comp is based on. After a few hundred dives I now enjoy taking things easy and not pushing my limits. After taking some tech classes where computers were not permitted by the instructor I found I could dive tables and with good buoyancy control and a smart plan have just as much, if not more, fun being conservative.
 
1) Are you monitoring both computers during the dive
2) Do you stuff the backup into a BC pocket and use it only if the primary fails
3) Do you stuff the backup into you gear bag and use it only when the primary fails.

For #1 or #3, does not really matter (Although #3 requires a proper transition since the backup has no idea what dives you have already done)

For #2 (my mode) your backup will be much more useful if it is running a similar algorithm or a more liberal one if you are doing multiple dive / days and dive with both so you don't have to miss subsequent dives due to a dead computer. The reason being is if the backup is more conservative than your primary, it may go into deco mode and lock you out while your main (more liberal) dc is humming along happy. At that point, the backup is worthless if your main computer dies.
 
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