Backup Computer Recommendations?

[kcprofessor]

Looking for some advice on a backup for an upcoming dive trip. The issues are that the trip will cost several thousand dollars in airfare plus a few more thousand for the liveaboard, etc. The upshot is that I do not want to miss a day of diving nor do I want a chamber dive! I have been using an older computer (Suunto HelO2) in gauge mode as the backup to my Petrel, and that works pretty well. The big problem is that IF the Petrel goes down, I can't get the Suunto out of gauge mode for 48 hours. Diving strictly tables is not the way I want to spend the dive trip so I am looking for a real back up computer that is compatible with the Petrel in that it would run on either the Buhlmann or VPM models. The computer doesn't need to have full trimix capability nor does it need more than a two or three gas capability. Ideally, it shouldn't lockout if I don't follow its profile. (If I use the Suunto as a full backup, I might as well take a sleeping bag to wait out the deco stops.) I am looking at this as an insurance policy for the trip. I would welcome any ideas.

 

[Doby45]

Find a cheap Petrel 1 or a Predator.

For Sale - Shearwater Petrel 2 SA

 

[tbone1004]

depends.

likelihood of petrel kicking the bucket is basically 0, and if you are diving the suunto in gauge mode then you are doing it for a reason, which means you are carrying tables around with you, otherwise why bother bringing it in the first place....

If you want a cheap one that is basically a throwaway, then get a DG03 from Dive gear Express and call it good. $250 and you're good to go. If the new Cosmiq computer had any information about their algorithm then that would be an option at $300, but realistically I'd just get a used Petrel 1 for around $400 and call it a day. It's big, but at least you know it's exactly the same as the other one so it is an actual redundant computer for you

 

[KevinNM]

You can stick your redundant computer in a pocket or some other convenient spot. It doesn't have to go on your wrist.

 

[BabyDuck]

^though of course remember to change gasses as needed.

yeah, go for a shearwater someone's selling to upgrade.

 

[ajduplessis]

I would not bother with another dive computer IMO, you already have 2.

 

[Fedaykin]

If you are diving with a group of 6 people, only 2 computers will be more than enough. Stick to group, dive when they dive, rise when they rise and deco when they stay for deco. I don't see any reason for buying a back-up dive computer.

 

[DevonDiver]

If you are diving with a group of 6 people, only 2 computers will be more than enough. Stick to group, dive when they dive, rise when they rise and deco when they stay for deco. I don't see any reason for buying a back-up dive computer.

What you "don't see" is probably due to significant inexperience and/or knowledge deficit in technical diving principles and practices.

 

[lermontov]

surely you must have a friend you can borrow one for a week or two

 

[stuartv]

Nitek Q for $399?

Dive Rite NiTek Q Advanced Nitrox/Trimix Dive Computer (V2) | Dive Gear Express®

Find a used SeaBear H3? I had a Petrel 2 and bought an H3. I used them both for a little while then sold my Petrel 2 and don't miss it at all. Right now, today, my ideal setup would be an H3 and a Perdix (for reason, see below), but I can't afford a Perdix right now.

Personally, I would avoid the Hollis DG03. It is BASED on Buhlmann. It is not Buhlmann and doesn't support Gradient Factors. They say the DG03 algorithm is PZ+ (Pelagic Z+), which is, I believe, proprietary. I personally would avoid any proprietary algorithm in a computer I'm using for tech diving. But, if you do want a computer that has PZ+, you may as well look for an Oceanic Geo 2.0 and get PZ+ and DSAT - and spend less money.

That said, if you are able to get a second Shearwater for around the same money, that would be very hard to argue against.

As a philosophy, I would prefer to have 2 different brands of computers for primary and backup on a tech dive. This would insulate me as much as is possible from the potential for encountering a firmware bug that produces the same erroneous result on both computers. However, in real life, the chances of that happening with Shearwater seem so remote that I wouldn't let that particular concern dissuade from using 2 Shearwater computers. (but it might well dissuade me from using 2 Niteks...)