Cheapest computer w/ Buhlmann GF control

[ScubaSamScubaStevesFather]

Hi,

I'm looking for advice on which backup computer I can buy used and at the cheapest price that has the Buhlmann algorithm with customizable GF. GF must be customizable so I can have the dive profile match my primary computer (Perdix).

I'm thinking a used Petrel might be my only option, but I'd rather go cheaper.

Also, any advice on the cheapest bottom timer/depth guage (Mares Puck Pro?) would be appreciated too as an alternative.

Thanks.

 

[Eric802]

Used Peregrine?

 

[brsnow]

Deep6

 

[Ski_Lounge]

Seac Screen goes for $300, and Deep 6 Excursion goes for $350. I think these are the lowest cost Buhlmann on the market. They only support preset gradient factors. I recently saw the Atmos Mission One for $350 on Leisure Pro, though normal price is $500.

 

[inquis]

The (hopefully) soon-to-be-released update for the D6 Excursion will have custom GFs.

 

[Stoo]

Given that your backup computer becomes your primary when your primary bites it, I think I'd be wary of changing brands.

I have two Shearwaters which I love, but both have failed at one time or another. Aiming for a used Shearwater is a solid plan, but I'd avoid bringing anything that doesn't "match" in to the mix unless you intend to just use it as a BT. On bigger dives, I wear both of mine and they're exactly in sync. If one died, it would be a complete non-event. I'm not sure you'd get that same "synchronicity" with a different brand.

 

[NYCrecdiver]

It's not cheap but I am looking at the Garmin Descent G1 as a backup to my Perdix. I can use it as a my daily smart, health tracking and workout watch. So it fulfills multiple missions.

 

[Cheizz]

If you're diving a Bühlmann GF computer as your primary, it is wise to look for the same algorithm and GF for a backup, right? Or could there be a different algorithm (or slightly different GFs)?

 

[NYCrecdiver]

If you're diving a Bühlmann GF computer as your primary, it is wise to look for the same algorithm and GF for a backup, right? Or could there be a different algorithm (or slightly different GFs)?

Yes. You'd like your backup to be as close as possible to your primary. I guess the importance of this depends though on what diving you do. If you're doing nodeco dives and you don't mind keeping an eye on 2 computers to make sure you are within limits on both of them, I guess it could work. If you violate your backup though and it goes into lockout mode, you no longer have a backup computer for say a second dive that day. I like diving with my Perdix as primary and G1 as secondary. Their medium conservative GF are the same so they tell me the same thing under water. The G1 is a bit limited in that it doesn't support changing GF settings to your liking but I dive with the Perdix and G1 defaults anyway.

 

[Belzelbub]

If you're diving a Bühlmann GF computer as your primary, it is wise to look for the same algorithm and GF for a backup, right? Or could there be a different algorithm (or slightly different GFs)?

Ideally, yes. Identical is preferred, but I wouldn't say it's absolutely required. Plenty of divers out there use different algorithms with their primary and backup. That's OK as well. Main thing is that the more conservative algorithm controls the dive, especially if that computer will lockout. Backup stuck in gauge mode is less than ideal.

The good news is that there are lots of options from different manufacturers that can work well together. My primary is a Shearwater, and my backup is a Garmin. Both have Buhlmann GFs with identical presets, and custom GFs. There are also options from a number of other manufacturers that would work. The Ratio line would work as well, but the presets are a bit different, and not all the "models" support custom GFs out of the box.