Affordable Dive Computers

[kevinpleong]

I think there is a more important thing to think about. Know when to call a dive.
At what point are you so hellbent on making the next dive that you make poor choices leading up to the bad choice.

You miss a dive. So what? Kick back, have a drink, enjoy life anyway. Reset, try again the next day.

I you pay a thousand dollars on a trip and want to go diving and can't because your computer dives and you have to now wait 18 hours before diving again it can be very difficult.

 

[wetb4igetinthewater]

I you pay a thousand dollars on a trip and want to go diving and can't because your computer dives and you have to now wait 18 hours before diving again it can be very difficult.

If you are paying thousands of dives to go on a trip, you should have a proper backup dive computer, even if your primary is a Shearwater.

 

[Garth]

Buy a used shearwater petrel 1. Cheap and works great. I see a few on the market now.

 

[jonhall]

want to go diving and can't because your computer dives and you have to now wait 18 hours before diving again it can be very difficult

The dive computer can't make you wait a certain amount of time before diving again. I had a Suunto Cobra which, as many will point out, has a very conservative algorithm. During a trip, on a second dive of the day, I went into deco and wouldn't have the time to complete a deep safety stop - did a couple of longer shallower stops and came up hoping computer wouldn't be locked - but it was. Diving the next day, I could still use my computer in 'gauge" mode - what it wouldn't do is calculate NDL, but give all other readings including air as it was air integrated. The dive op did give me a wrist computer to use, but I would have been comfortable diving without it and keeping closer to my buddy, who uses a dive computer with a less conservative algorithm. Basically, all we do are recreational, no deco dives so I wasn't too worried about it.

Whether a diver's computer went into deco after a first dive of a 2 tank trip or, like in my situation above (staying locked on the next day of diving), wouldn't switching over to a backup circumvent the safety you are supposedly using the dc for anyway?

Not saying a 2nd dc isn't a good idea, but having one locked out can't prevent you from diving.

 

[inquis]

wouldn't switching over to a backup circumvent the safety you are supposedly using the dc for anyway?

You take both computers on all dives. The backup then has accurate tissue loading information. The point is to guard against a computer failure.

If you cut a deco stop short and lock both computers, that's your fault and not really the point of having a backup. If you feel the conservatism safely compensates for your actions, it's obviously your call whether to continue diving. However, choosing a computer that doesn't lock you out would be smarter than relying on a buddy's computer.

 

[Centrals]

I use two dc in diving and a third one stay on land.
If I have to use the third one because of a failure of one of the other two then it will be used as "back up". However, the more conservative one(shorter ndl) will be the main one.
All these three dc are running on various algorithms(DSAT, PZ+ and ZHL8).

 

[FishWatcher747]

Yes and no. I am aware you can buy dive computers one eBay but I would like to purchase two that are on the same algorithm, I can change the batteries easily if needed and most importantly I would like it to be reliable...

There is no prohibition to buying 2 used fully functional computers that you can change the batteries that run the same algorithm. That's what I did.

Edit: They were separate purchases so it does take a bit of time. Someone has to benefit from divers selling their out of fashion computers to get a Shearwater.

 

[Gandalf-the-Diver]

However, choosing a computer that doesn't lock you out would be smarter than relying on a buddy's computer.

... and we all know which computer brand that is

 

[Belzelbub]

... and we all know which computer brand that is

There are a few brands that would fit that description. My primary and backup are different brands. Neither will lock me out. Technically, one will, but allows the user to disable the lockout.

 

[jonhall]

You take both computers on all dives. The backup then has accurate tissue loading information. The point is to guard against a computer failure.

Also true if using only one computer.

If you cut a deco stop short and lock both computers, that's your fault and not really the point of having a backup. If you feel the conservatism safely compensates for your actions, it's obviously your call whether to continue diving.

Kind of my point to the OP. The computer can't prevent you from diving. The OP is simply looking for an option for if he gets locked out of his primary. It's not a case of "Oh,oh! My computer locked on me and I'm not sure if it's safe to dive again." It's more like "Shucks!! My computer locked on me. Glad I have a backup so it will calculate NDL on my next dive."

I would suggest not purchasing 2 computers with the same algorithm, as the OP says he wants to do. Wouldn't it be better to have 2 computers with different algorithms, assuming 1 to be less conservative than the other? OR, as suggested by others, get 2 of the same, less conservative computers, and hope the diver pays attention while he/she is diving?

When I first started diving with only a handful of dives under my weight belt, if I would have had 2 computers and one locked on me and one didn't, I probably would have been worrying about which computer knew me best......no, I probably would have jumped in to dive again!!