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Can I use a Cobra 2 as a backup computer, NOT hooked up to a hose?

Discussion in 'Computers, Gauges, Watches and Analyzers' started by spopes, Mar 31, 2012.

  1. spopes

    spopes Garibaldi

    # of Dives: 25 - 49
    Location: Sioux Falls, SD
    3
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    I feel like this is probably a really dumb question. I just switched to a VT-4 for a trip to FIJI. I want to have a backup computer. I have been considering selling my Cobra2, which works great, and has the QD. Can I dive with the computer not hooked up to an air hose, i.e. in a BC pocket or clipped to a d-ring? I don't know if having that connection exposed means I will flood my computer?

    Thanks in advance.
     
  2. scubadada

    scubadada Diver ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Philadelphia and Boynton Beach
    4,435
    1,279
    113
    Hi spopes,

    I'm reasonably sure you can use your Cobra 2 as a backup, not connected to a HP hose, but I would ask the question on the manufacturer thread and get the answer from Suunto. That being said, the decompression algorithms will be quite different, especially if you use the DSAT algorithm without the conservative setting on your VT 4. The Z+ algorithm will be more similar and can also be made more conservative. I'm sure you can find a combination that would match pretty well if you wanted to. It may not be that important that the computers match as you would only be using the Suunto if the Oceanic went bad. If you don't dive with a SPG, you would have to take your HP hose with you to use with the Suunto if the Oceanic was not working.

    My primary computer is a VT 3 and by backup is a Geo 2. I have a SPG in my bag I've never had to use with this pair but have resorted to my backup computer and SPG once in the past during a week long trip where the redundancy proved very valuable.

    Good diving, Craig
     
  3. spopes

    spopes Garibaldi

    # of Dives: 25 - 49
    Location: Sioux Falls, SD
    3
    0
    0
    Thank you so much for the reply. I will re-post in the manufacturer thread. I have to admit I like Suunto's computer software, and Movescount much better than Oceanic's logbook software. However, I think I like Oceanic's on-unit software better. I'm not too concerned about the Suunto being more conservative than the Oceanic, in the situation of a backup computer. I am hoping I can just use the Suunto for backup, and to still upload my dives to Movescount.
    We'll see I guess. :)
     
  4. scubadada

    scubadada Diver ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Philadelphia and Boynton Beach
    4,435
    1,279
    113
    You'll have to make sure you don't go into deco with your Suunto, not take care of the deco obligation, and get locked out for a period. That would take care of your backup computer. If you leave it in a pocket and don't monitor it, this might just happen if you dive your Oceanic to limits with the DSAT algorithm.

    Personally, I would not want my dive to be controlled by a more conservative computer backup than my primary computer. That's probably the main reason my primary and backup run the same algorithm.

    Enjoy Fiji,

    Craig
     
  5. sharkshark

    sharkshark Angel Fish

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    Resuscitating this thread for giggles - the scnario of something like a Cobra as backup does sound a bit nuts, but having suffered my first computer failure, I'm seriously thinking backup. The goal will be to get a Cobalt one day, but for now I'll be getting a Cobra3 to replace my dead Cobra 1. Yes, I'll run into some issues regarding more silly deco dive plans, but given that I'm almost always diving well within limits, and that really all I want is backup depth/air/results of nitrox usage for multi-dives, I figure the second comp can't hurt.

    So, that being said, how crazy would it be to have =two= Air Integrated comps hooked into the same first stage? I'd move my Cobra to attach well out of my way (but physically available in time of the unlikely failure of my primary computer), but for the most part I'd just have it out of the way.

    Yes, it's overkill, but it seems like not a bad solution, and frankly will likely be less expensive than getting a similar spec'd secondary computer.

    Or, of course, I could just sell the Cobra when I buy a Cobalt. :)

    Thoughts?
     
  6. sharkshark

    sharkshark Angel Fish

    44
    3
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    One last bounce - anyone ever crazy enough to do two air integrated hose-tethered computers?
     
  7. TravisD

    TravisD Assistant Instructor

    # of Dives: 100 - 199
    Location: Westminster, MD
    618
    70
    28
    What problem are you trying to solve?

    Seems to me like now you have more points of failure to deal with, all of which would send you back to the surface, along with another hose to deal with and more stuff to manage in general. How common is it for the computer itself to fail, vs. things like hoses and o-rings? If they're not with you on the dive, they can't fail and end the dive for you :)

    If it were me, I'd add it to the save-a-dive kit. That way it's there if you need it, but out of harms way when you don't. At some point you start picking up other spares like a 1st and 2nd reg, and now you've got a nice piece of kit that you or another diver could use in a pinch.
     
  8. sharkshark

    sharkshark Angel Fish

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    You have a point... I guess I'm just trying to avoid the failure I had with my first Cobra, that if it had happened in the middle of a long trip w/o a spare would have been kind of annoying... I dive well within limits, but still, having a spare computer doesn't seem particularly stupid.

    That said, I am interested in picking up one of the Atomics later this summer likely, but have the Cobra 3 replacement for now. The thought was to avoid having to buy a third comp, plus auxiliary air gauges - run two air integrateds, and you'd good for redundancy on all fronts.

    I dunno, it's likely too hardcore for what I need it to do, but it would kind of justify having owning two premium air integrated systems. I just didn't know if there would be issues from the first stage of running both systems at the same time - have no idea how it possibly could be an issue, but it's usually dumb in this sport to assume such things.
     

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