Backup computer for when your main fails while in diving trip ?

[scubadada]

Hello,
My wife and I dive recreationally, lately we do mostly LOB.
Her main computer is a Perdix, and she gave me a Perdix 2 for Christmas.

We are currently on a LOB in the Red Sea, and my wife's Perdix died on the very first dive. One of the push buttons failed, fell off and the computer flooded.

Fortunately we also brought our old Suunto Vyper, and she's now using that. Last trip it bailed me out when my Eon Core started doing strange things.

But the Vyper is getting old and may not be too reliable.

My wife's Perdix will obviously get fixed, but we're thinking about getting a new computer to carry as a backup of the main ones if there are surprises.

We were thinking a Peregrine would be a good option. Do you think it makes sense ? Any others you would recommend ? Should we just go for an inexpensive Zoop or Vyper Novo and save the money ?

Thanks for your feedback.

It's completely unnecessary to use a 500 Dollar spare computer for NDL dives. In NDL buddy diving the buddy is spare gas and computer/depth gauge, that in fact is industry standard.
I don't know if you work a normal job for your money but in my local dive club, many people have work many hours and save their money to buy gear and go on trips. Telling people to just spend 500 or even 1000 Dollars per person because of some made up safety issue is weird to me. You also can't 'spread 500 Dollars over five trips'.
Again, the question was if a cheapo computer will do as a spare for trips. It's does.

Actually, the OP and his wife are not average, casual, recreational divers and state they mostly dive liveaboards. Their primary computers are Shearwaters, running Buhlmann. They have had to use their backup computer, an older computer running a different, probably very different, deco algorithm twice recently. They are afraid that their current backup computer may not be reliable and are asking for assistance in choosing another.

Having a backup computer in these circumstances is not only a safety issue for an acute computer failure but will allow continued safe diving for the remainder of a liveaboard trip. Having one backup for a buddy pair of divers is not optimal but is better than none.

Choosing a backup computer running the same deco algorithm as the primary computers is a good choice. I would have one of the divers use it from the beginning of the trip. Their suggestion of a Shearwater Peregrine as a backup is a perfectly good one. There are several other computers running Buhlmann with custom GFs and/or presets that might be additional, perfectly good alternatives, some at lower cost than a Peregrine.

 

[Divin'Papaw]

Plenty of people have said in this thread that the spare computer should run the same model and should be carried on every dive. So 4 computers for a buddy team for NDL vacation dives according to this logic. Go back and read what people said.
Maybe it is standard where Jim lives in Florida, most places it isn't.

If you think every tec agency requires people to have 2, 4 or 6 computers, so be it. I don't really care and it's not what was asked by the OP.

I think we may have a reading comprehension issue here.

First, discussing whether a backup computer should run the same algorithm as the primary is saying nothing about the backup computer being required. Second, I've seen NO ONE say that they viewed a backup computer as a REQUIREMENT for recreational diving. Lots of people discussing what they dive and why they dive it and what the benefits are. That is NOT the same thing as saying they view that as a requirement for recreational diving. Please, read what people post and don't read INTO what people post.

As to your second comment, I NEVER SAID every tech agency requires 2, 4 or 6 computers. Again, you're reading INTO my post. What I said was, with every tech agency I'm familiar with, IF you are diving your computer as your primary dive execution tool on a technical dive, you either MUST have a second redundant computer OR you must have a bottom timer and cut tables.

Hope that clears things up, but I have my doubts.

 

[boulderjohn]

So let me get this straight. According to most of the users in this thread giving advice, all rec divers should carry 2 computers on every dive on every trip and otherwise can't keep diving on that same trip safely? Really?

First, discussing whether a backup computer should run the same algorithm as the primary is saying nothing about the backup computer being required. Second, I've seen NO ONE say that they viewed a backup computer as a REQUIREMENT for recreational diving. Lots of people discussing what they dive and why they dive it and what the benefits are. That is NOT the same thing as saying they view that as a requirement for recreational diving. Please, read what people post and don't read INTO what people post.

I think the overwhelming majority of divers should play the odds and dive with only one computer. I have gone on multiple multi-week diving vacations with two friends who only dive one computer, and, so far, no problem. In fact, I have never seen a computer failure cancel an NDL dive, and I have racked up quite a few such dives. If it happens, well, it happens. It's not a huge loss to miss a dive.

I only started using a second computer for tech diving, and then I I started using both for recreational dives because I had them, so why not?

 

[berndo]

Actually, the OP and his wife are not average, casual, recreational divers and state they mostly dive liveaboards.

The OP is not Merican. It's common to do liveaboards in the red sea. How this not average rec diving, I don't know. I hardly know a club around here that doesn't go to Egypt once a years. Not that this has anything to do with the point I made and you're trying to avoid.

Having a backup computer in these circumstances is not only a safety issue for an acute computer failure but will allow continued safe diving for the remainder of a liveaboard trip. Having one backup for a buddy pair of divers is not optimal but is better than none.

Ok on last time I tried to break it down for you and you tell me what's wrong without giving any silly 'I don't buddy dive' stories.

Diver 1 and Diver 2 to go diving in a buddy team and on day two, the computer of Diver 2 fails. They continue the dive. Before the next dive, Diver 2 graps the spare cheapo computer and they go on the next dive. Now, obviously the spare doesn't have the last dive in it. But it's not an issue because, (as you would normally do) follow the most conservative computer in the team. If the Diver 1 computer gives a shorter time you follow that as you would on EVERY dive ever in a team. On the day after you do the same. The likelihood of Diver 2 getting bent is just as high as Diver 1 getting bent. The worst that can happen is that the cheapo spare is more conservative and ends up giving you less dive time than the other computer would have given for the rest of the trip, if it is less conservative they keep following what Diver 1's computer says anyways.

Now explain to me what the risk is and at what point this is diving with 'blind faith'.

I get it, it doesn't apply to solo diver or diver who 'dive with a group but not with a buddy' (for some reason). It also doesn't apply when some idiot buddy dives 10m below or above the other buddy. Obviously.

 

[rob.mwpropane]

Actually this thread is an example of teaching dogma using fear porn.

The earth will end and everyone is going to die if you are doing recreational NDL dives and your computer dies. You better stop diving immediately or you are certain to die a horrible death.

It doesn't matter if you have a spouse or trusted buddy and you are diving the same profile as their computer.

Lol.. I would not want a buddy up my ass at any point on any dive.. checking my wrist, seeing what depth, how much time.. what a mess.

Nobody said die, we just think it's the responsible thing to do. Diving and "winging it" don't go together well, that's all.

 

[rob.mwpropane]

The OP is not Merican. It's common to do liveaboards in the red sea. How this not average rec diving, I don't know. I hardly know a club around here that doesn't go to Egypt once a years. Not that this has anything to do with the point I made and you're trying to avoid.


Ok on last time I tried to break it down for you and you tell me what's wrong without giving any silly 'I don't buddy dive' stories.

Diver 1 and Diver 2 to go diving in a buddy team and on day two, the computer of Diver 2 fails. They continue the dive. Before the next dive, Diver 2 graps the spare cheapo computer and they go on the next dive. Now, obviously the spare doesn't have the last dive in it. But it's not an issue because, (as you would normally do) follow the most conservative computer in the team. If the Diver 1 computer gives a shorter time you follow that as you would on EVERY dive ever in a team. On the day after you do the same. The likelihood of Diver 2 getting bent is just as high as Diver 1 getting bent. The worst that can happen is that the cheapo spare is more conservative and ends up giving you less dive time than the other computer would have given for the rest of the trip, if it is less conservative they keep following what Diver 1's computer says anyways.

Now explain to me what the risk is and at what point this is diving with 'blind faith'.

I get it, it doesn't apply to solo diver or diver who 'dive with a group but not with a buddy' (for some reason). It also doesn't apply when some idiot buddy dives 10m below or above the other buddy. Obviously.

Same scenario.. you lose your buddy. Now what? What is the contingency? Just end the dive?

I spent $4000 to get to Timbuctoo and now I have to cut my dive short because I wasn't carrying my $200 backup?

 

[berndo]

Actually this thread is an example of teaching dogma using fear porn.

It is. It's also a good example for group think. You don't even need a computer to safely plan and do a dive. You certainly don't need 4 computers for 500-1000 bucks a pop for a team of 2 doing single tank dives on vacation.

 

[Belzelbub]

We were thinking a Peregrine would be a good option. Do you think it makes sense ? Any others you would recommend ? Should we just go for an inexpensive Zoop or Vyper Novo and save the money ?

Well, hopefully all the back and forth hasn't scared you away from this thread.

A Peregrine would be a great backup. Especially as you already have Perdii. You'll already know how to use it. One thing, thought to be effective, the backup needs to go on the dives along with the primary. You could save some money and some wrist space by getting something a bit cheaper/smaller, but I wouldn't recommend a Suunto. Especially if you are doing LOBs. The Suunto algorithm will start to disagree with Buhlmann and if you aren't watching this closely, it may lock itself up in protest.

Lots of dive computers these days are coming with Buhlmann. That will be best as it will match what you are currently using. DSAT (Oceanic) or PZ+ (Oceanic, Aqualung) would be some others that I wouldn't mind. DSAT would be more liberal than Buhlmann, PZ+ is more moderate, but based on Buhlmann.

 

[Divin'Papaw]

It doesn't matter if you have a spouse or trusted buddy and you are diving the same profile as their computer.

There is no such thing.

 

[berndo]

As to your second comment, I NEVER SAID every tech agency requires 2, 4 or 6 computers. Again, you're reading INTO my post.

Read again. I said: Whatever you think, I don't care.

There is no such thing.

A buddy team does have the same profile. Whenever I dive with a buddy we either have the same NDL/deco time or it's very close. (When diving the same deco model, of course).