Value in having two computers?

[Jase Carter]

I really like the Aqua Lung i200C I purchased this fall. I also recently bought a used regulator (Legend LX 2016) that came with a Suunto Cobra 3 and compass. I had no intention of keeping the Cobra 3 but other divers have encouraged me to use both, saying things like "never hurts to have a backup," "good to be familiar with two different devices and calculations," etc. I will likely use the Cobra 3 for the first time this weekend in a cold water dive in Southern Illinois.

I try to be fairly zen when diving and like to have a minimalist setup, so I don't think I want to have another screen to decipher. A simple stainless steel analog gauge sounds fine to me and I just sell the Cobra 3.

Thoughts?

Other info: I received my Advanced Open Water in 2005, but have only gotten back into diving this year; only done 25 dives to this point; will primarily be doing warm water, travel dives, but also some local cold water dives here in the Midwest; don't anticipate ever being a "tech" diver besides possibly taking a cave certification sometime.

 

[Addicted2H2O]

I'd say if you already have them both, then maybe keep the Suunto for backup. Or you could always sell it and get a basic non AI puck type computer to keep on a D-ring as a backup. I certainly understand not wanting another hose to have to work about with the Suunto. But there's something to be said for redundancy. Both computers are electronic and that being the case there's always a chance for failure. Electronics....water.....'nuff said.

 

[Diver below 83]

Once I get a perdix ai i plan to rock my mares quad as a back up

 

[wetb4igetinthewater]

I'd make sure the algorithms match. If your backup is more conservative and you ignore it as you focus on your primary, then at some point the naughty alarm is going to be sounding when you get back to the surface. It may lock you out for 48 hours too if you don't take out the battery.

I like having two Shearwaters. Pricey yes, but for tech and vacation diving, a necessity in my book.

 

[divad]

I try to be fairly zen when diving and like to have a minimalist setup, so I don't think I want to have another screen to decipher. Thoughts?

Well,.... when the Zen-Hits-the-Fan,... are you cool (and down) with that?

 

[loosenit2]

having a backup can be helpful. Of the two computers you mentioned another significant difference in the two is that the Cobra3 is Air Integrated. If you don't keep the Cobra 3 on your set you will have to add an SPG to it to monitor your air as the I200 is not air integrated. So it is possible to use both the cobra3 and the AL 200i, you will just have to decide which computer you are going to follow.

Note that you can also dive the Cobra3 in guage mode where it just gives you depth, air pressure and time, but know that if you dive it in guage mode you are locked out from using it as a computer until the no-fly timer has counted down.

 

[Jase Carter]

All great points. I will keep it, making sure it is less conservative than my primary computer (i200C).

Thanks!

 

[drbill]

I almost always dive with redundant computers, Back when I used just one, I had several instances of battery failure without warning. One battery failed when the battery indicator read 38% remaining battery life.

 

[markmud]

Hi Jase,

I was onboard Vision (sister to the former Conception) at Santa Cruz Island. Santa Cruz Island is the best Northern Channel Island to dive, in my opinion.

I jumped in the water and was told by another diver that I was blowing bubbles. It was my HP hose. I had dived 3 times that day and wasn't done. No problem. I used my back-up computer because it had my nitrogen data. I dived on. Without that second computer, I would not have dived anymore that day.

If I were you, I would keep the second string computer, or sell it and buy a puck computer as a back-up.

cheers,
markm

 

[Neilwood]

A lot depends on the diving you plan to do.

Single day with 2 dives - not a big issue if a computer craps out on you. Call the dive and go home.
Multi day, multiple dives (such as a liveaboard) - big issue if a computer craps out. You could have to miss a number of dives if you can't work out your tissue loading and possibly resort to tables (which are not the best option as they WILL restrict the diving you can do compared to others on computers)

Another consideration is distance to dive site - if you have driven a number of hours to get to a site, it would be a PITA to have to call a days diving due to a simple computer issue.