Computers and backups - looking for pearls of wisdom from the more experienced

[tursiops]

I Fully agree; in fact, I cannot understand why you would not want to have your backup with you on every dive. If it is truly to be used as a backup, a backup stored above water won't be much good to you during a dive in which the primary fails or on the dive after a primary failure.

Concur.

 

[Wibble]

What’s worse than not having a backup when you need it?
Knowing it’s back up on the boat when you need it.

 

[Jonn]

Jonn, I'd recommend you to always dive both computers on a big trip. If you're switching to a fresh computer after any significant amount of diving on a multi-day trip your NDLs are going to be off, maybe dangerously so.....

That’s a good point. Of course a backup computer I don’t take with me every dive will not have current tissue data and will not be able to protect me. In the unlikely event of my primary computer failing I would be faced with skipping a day of diving until I was completely desaturated before proceeding with the backup. I’m trying to split the difference in risk here: avoiding the burden of wearing the backup in the water and accepting the risk of loosing a dive or three, while accepting the smaller burden of having the backup in my save-a-dive kit and avoiding the risk of loosing the whole trip. It’s a compromise, like many things, but I’m only risking fun and expensive dives here, not my health.
In my particular case my backup is my old hose computer that needs to be plumbed into my reg. Makes it not as good at its job as a backup, something like the specialized Oceanic BUD would be better in every way, but the price was right! My point is that in tech diving the backup computer tracks the decompression schedule that keeps you from dying, but in rec diving it keeps you from having a bummer vacation. Less important, still worthwhile,

 

[tursiops]

I’m trying to split the difference in risk here: avoiding the burden of wearing the backup in the water and accepting the risk of loosing a dive or three

It is a tiny burden to have the backup with you. And if plumbed in, even less burden. I don't understand your reluctance.

something like the specialized Oceanic BUD would be better in every way

Some just put the backup in a pocket or hang it on a chest d-ring.

 

[Jonn]

It is a tiny burden to have the backup with you. And if plumbed in, even less burden. I don't understand your reluctance.

Some just put the backup in a pocket or hang it on a chest d-ring.

It’s an extra hose on my reg. (If I admit I dive an integrated octo I’ll get more flak here, so don’t tell anyone, but I don’t like extra hoses…) There’s also the battery: I’ve had a great deal of bad luck changing batteries on PPS computers and am reluctant to waste their charge. As you say it would be a small burden regardless, but it’s a pretty tiny risk of my super-reliable new Perdix failing in the first place. I worry about it enough to maintain my old computer and toss it in the box, I don’t worry any more than that.

“One is none, two is one” only counts for stuff you really need. I don’t need any computer to surface from a rec dive, and I don’t really need to dive every day either. That’s how those cluttered looking divers that spend more time managing their gear in the water than actually diving happen: it seems to multiply while your back is turned!