When to buy a new computer?

[TrimixToo]

If it's not the same make and model (or you forget to set the right mix), then you might find your backup is bent into one hundred nazi crosses when you need to use it, and you have no computer for 24 hours. Whereas on the "clean" backup you can up the conservatism to somewhat compensate... It's not optimal either way.

Or, you can run the dive using the more conservative of the two. Then, if it fails, you can choose whether to pad what the less-conservative one recommends or just run the remainder of the dive with it.

Also, if something goes wrong, you can ascend using the less conservative one. Some technical divers do this on purpose by setting different levels of conservatism in their (perhaps identical) computers. For example, my Petrel is set conservatively, and my VR3 is not. There is often a 10-15 minute difference in time to surface between the two.

 

[dmaziuk]

It's all well and true, but the OP specifically stated he doesn't need a backup computer and that immediately prompted the SB mantra "two is none, one is gone, YOUR GONNA DIE!!!" or however that goes.

I agree, BTW: I don't need a second computer myself, and for pretty much the same reasons. I would "upgrade" if I had money to drop on a new toy, and the new toy had WAI. Or if that mythical creature from deep 6 came into being. If that happened I'd probably use both, just to see how their calculations differ on the dives I do -- but that's because I'm a programming geek, not because I need a backup computer.

 

[scubadada]

I have been diving with my computer for at least 10 yrs and it works great for me. Its an Aeris Elite T3 hoseless setup. Never had trouble with it. Change the batteries every yr even though they do not get that much use.
I dive 2-3 trips per yr with 1-2 weeks diving per trip. One trip is usually a live aboard, sometimes to exotic places.

I use nitrox on nearly every dive. My depths are nothing special. Been to 120-130 ft at the Blue Hole and U-352 but rarely go past 90-100 ft as there is usually no pressing reason to go deeper. I never plan to be a technical diver, never plan on cave or penetration diving.

I do photography and might be considered a photographer that is underwater instead of a diver that photographs. My dive buddies are always new to me each trip so sometimes we are not as close as one might like. Please, not looking for any speeches on new dive buddies or allowed distances. Any long term U/W photographer knows how it is. Unless paired with another serious photographer, few dive partners have the patience/interest to stay close while you work with a subject.

Dive boats generally have a computer available if one fails but of course, you have one dive when it fails and have to deal with it. I would likely be able to find a replacement for rent most places I dive after a failure. There have been trips when this is not true, such as to Indonesia in remote locations but that is not my typical trip.

Sooner or later, computers will fail. Its not like we get computer servicing on the internals like a regulator. So do you replace it before problems? If so, what criteria do you use for WHEN?

I have an Oceanic VT3, essentially the same computer as your Elite T3. I've only had it seven and a half years but it has 1018 dives and 1067 hours on it. I intend on diving it as my primary until it dies. I've been diving a Geo2 and a SPG as backup for six and a half years. The VT3 and the Geo2 are identical in NDL. I am loathe to miss a single dive or interfere with a series of dives. I've only used my backup twice. My advice would be to dive a backup, get a new primary computer when the current one fails.

 

[Centrals]

I had computer failure twice and had also seen that happened to other divers while above or under water. No big deal if that was your last dive of the trip but unfortunately life is never perfect. So what would you do if that happened on the 1st day on a liveaboard and there is none available for rental or whatnot? Use the table with a diving watch/timer for the next several days! I learnt my lesson and dived with two computers with identical algorithm and when one of them died, I bought a more liberal one(US$200.00) and use it as back up.

 

[Johnoly]

.. So do you replace it before problems?

Maybe spend the money instead on a small pony tank and reg...... 'puters don't save lives.

 

[Damselfish]

Dive boats generally have a computer available if one fails but of course, you have one dive when it fails and have to deal with it. I would likely be able to find a replacement for rent most places I dive after a failure. There have been trips when this is not true, such as to Indonesia in remote locations but that is not my typical trip.

Sooner or later, computers will fail. Its not like we get computer servicing on the internals like a regulator. So do you replace it before problems? If so, what criteria do you use for WHEN?

I'd say the right time to buy a new computer is when you need/want features you don't have. It's not like at the beginning of dive computers when there were more fundamental changes going on.

"Sooner or later, computers will fail." - this is not actually true. The comparison to a regulator doesn't quite work - aside from the battery there's not much to break or wear out in a dive computer. I think dive computers tend to fail either when they're newish, or when someone screws up a battery replacement and they leak. Good chance a computer you've had 10 years will keep on going for a long time if you don't flood it. If the computer has some kind of battery level indicator, I wouldn't open it up more than necessary. (The regulator comparison does work there - in my experience both are more likely to fail after service.)

It's all well and true, but the OP specifically stated he doesn't need a backup computer and that immediately prompted the SB mantra "two is none, one is gone, YOUR GONNA DIE!!!" or however that goes.

Unless the original post was edited, I don't see where the OP felt strongly against a backup, just that they could probably get one from the boat. (Don't really see "YOUR GONNA DIE!!! comments either.)

If someone is doing liveaboard trips - especially far flung exotic ones, but even "regular" ones - a backup computer is not a bad idea. Obviously not everyone doing that has one or feels it's necessary. But borrowing a computer that has no clue of your current decompression status will likely mess up more than one dive (and no, tables are not a useful backup if you've been doing typical liveaboard diving.) Getting a second computer would ease whatever concern the OP might have about diving with a 10yo computer. It might also make someone feel less compelled to replace a battery that doesn't really need it yet, reducing the probability of a failure in the first place. I'd say they don't _need_ a new computer, or a second computer. But if there's an urge for a new toy, it makes sense to keep the old computer and have a backup. (The old backup might by handy if the new one fails. Even having different algorithms is not that hard to manage unless they're crazy different, as said you stay in the limits of the more conservative one. Unless you've got 2 very different algorithms and are pushing the time on the more liberal one, it's at most a minor nuisance occasionally. (I've done it.)

 

[Jim Lapenta]

The time to buy a new computer is when you want to.

 

[dmaziuk]

"Sooner or later computer will fail" is actually true. Sensors in particular don't last forever, plastics get brittle with age etc. There's a thread right now about 3D-printing a battery cover for an old aeris computer because the coin slot in the original one disintegrated. And while most electronic components fail, if they fail, when first powered-on/warmed-up (or shortly after), some do have a limited life span. Dive computer-type devices should not have any e.g. electrolytic capacitors, but who knows.

 

[Neilwood]

"Sooner or later computer will fail" is actually true. Sensors in particular don't last forever, plastics get brittle with age etc. There's a thread right now about 3D-printing a battery cover for an old aeris computer because the coin slot in the original one disintegrated. And while most electronic components fail, if they fail, when first powered-on/warmed-up (or shortly after), some do have a limited life span. Dive computer-type devices should not have any e.g. electrolytic capacitors, but who knows.

Agreed - like everything in life there is a limited life. At some point it will fail- it is just a matter of when.

I have to say the best time to buy a new DC is whenever you want to. I replaced my £150 Cressi Giotto with a £800+ Shearwater Perdix AI despite nothing being wrong with the Giotto. Why? Because it had a nice big screen (that I could easily read in murky waters/night dives), was easier to operate (despite it only having 2 buttons instead of 3), was bigger. Did I need to buy it? Hell no but I am so glad I did.

 

[broncobowsher]

I replaced my decade + Oceanic computer because I found it a pain to use and there are much better computers out these days. Stepped up to a Shearwater. But what to do with that old Oceanic? I kept it in the console. Not that it does much, but it is a backup or at least a sanity check. I can now log more then 10 dives, don't need to find a serial port to download, can customize the display (along with just about everything else). I have modern decompression algarythims. I can review dive profiles on the computer at the dive site.

While the old computer did work, and still does, the upgrade was well worth it.