Diving with 2 different computers?

[rhwestfall]

They don't have multi-gas capability? I used to use Cochran computers many years ago but haven't used one in over 15 years.

They do, but it is pre-programmed auto switching, so it really is "plan the dive, dive the plan". I just used it for single gas, and is great that way. Actually, the wife really likes it as it is very readable, and can also be console mounted (yuck! - but what she likes)

YMMV

 

[mmerriman]

you'll want 2 computers with the same algorithm

 

[BoltSnap]

They do, but it is pre-programmed auto switching, so it really is "plan the dive, dive the plan". I just used it for single gas, and is great that way. Actually, the wife really likes it as it is very readable, and can also be console mounted (yuck! - but what she likes)

YMMV

I used to have the AI version. I owned Cochran computers from the first version for many years. I was also one of their first dealers. They were the pioneers of AI hoseless dive computers since the early to mid 90's. It took them several years to make their products reliable enough to dive however.

 

[rhwestfall]

@BurhanMuntasser : It was in the early 90's that I bought my first computer. Cochran was about the only company that made one that didn't lock you out, always calculating a solution no matter how bad you screwed up. That was the reason I bought a Commander Air. It served me well until I took some time off, and it "bricked". They gave me an incredible deal on an EMC20H that I dove until the Shearwater craze began. Got a Petrel1, and a month later the Petrel2 came out (wow - bad timing)...... Pulled the trigger on a Pedrix AI just before the Teric came out, but I likely wouldn't have gotten one anyways (at least for now).

 

[scubadada]

you'll want 2 computers with the same algorithm

All you really need is a backup that is the same or more liberal than your primary computer, so that the primary controls the dive.

I have been diving an Oceanic computer running DSAT since 2002, nearly 1800 dives (Pro Plus 2 until 2010, VT3 since). My 1st backup was a Cochran EMC-14, it worked perfectly as the deco algorithm was slightly more liberal than DSAT. I then dived an Oceanic Geo2 running DSAT for many years, it ran within 30 seconds of my VT3. About 3 years ago, I bought a Dive Rite Nitek Q, so that I could learn Buhlmann. The relationship between Buhlmann and DSAT is not perfectly straightforward for 1st and repetitive dives. I have posted on this topic previously. After a while, I was able to get them to match up relatively well. Just 3 months ago, I bought a Teric, a fantastic computer.

I was given a Dive Rite Nitek Duo in 2008 and dived it for 1 dive as a backup. Its proprietary Buhlmann variant was a little more conservative than PZ+. I did not have the time to clear its lengthy decompression obligation and put it into violation gauge mode. This is my example of using a backup computer that is significantly more conservative than your primary computer. I was easily able to find a new home for the Duo, it is still being happily dived today.

 

[FF / EMT]

And what's going to happen to the Teric

are you going to smash it mining for rocks during your dive
or watch it swimming off into the distance when the shark takes your arm

I'm not much for redundancy but if I'm going to take a machine gun the backup will not be a stick

Would it be a rock?

 

[drbill]

I dive with two computers, one a bit more conservative than the other. I view it as giving me a range, although I generally follow the more conservative one.

 

[outofofficebrb]

As others have mentioned, you don’t need the same computer or even the same algorithm. If you have different ones, just ensure you dive according to the more conservative one and use the more liberal one as a backup or you will upset it or lock yourself out depending on the computer and the diving you are doing. If you were to get a Teric, that would mean using your Suunto as a primary and your Teric as a backup. That defeats the purpose of a new Teric so I don’t suggest that.

I used to have 2 Suuntos as a primary and backup. I purchased a Perdix and sold both Suuntos to get a backup Oceanic (Veo 2) which runs DSAT, one of the most liberal computers. It is a perfect backup and even with repetitive diving for 11-12 days mostly 4 dives a day but a minimum of 3 on low conservatism (liberal) on the Perdix, it works great. No issues. I follow my Perdix and just keep the Oceanic tucked away. You could also look at a Geo or OCi depending on your budget. Or you could use the BUD or Pro Plus line.

 

[DBPacific]

Pick one and use it, if it fails then use the there other as a backup, don’t use both at the same time

There is no point in keeping a computer as backup unless it has been on your dives as well. Otherwise if your first computer fails and you switch to your 'backup' during the same day, it'll give you incorrect NDLs and won't be accurate for dive planning or safety. Either dive them both at the same time with one keeping as backup or only dive with one and take the day off after that computer fails before using the second.

 

[BoltSnap]

Pick one and use it, if it fails then use the there other as a backup, don’t use both at the same time

This is NOT correct unless you are going to take a 24 hour time out from diving to be able to switch to the second computer that was sitting on the surface and not keeping track of your residual nitrogen. If you want to use the back up computer to continue diving without losing time sitting on the surface to offgas, then your back up must be with you diving at the same time your primary computer is with you.