owning multiple computers

[doctormike]

So, the AL is correct if you're only using that, but it's wrong if you also carry the Zoop with you?

Well, that would be wrong and if you interpreted my statement that way, well, it wasn't what I meant. There is a gold standard "true" method of recording the depth and time and gas being used. Both computers should do that accurately and the same. What they calculate after that is up to each computer. But, the point is that if you do what I said (set both to the correct FO2 and dive with both), then either one can die and you can go on with dive #2 with the one that is still working. And it will correctly calculate your NDL and ascent based on its algorithm (unless it dies, too)

I guess my point is that "correct" and "wrong" miss the issue with multiple gas models, dive computers and algorithms. "Correct" and "wrong" imply that there is some actual degree of tissue loading and different models are using different methods to approximate it. This is not the case.

Different models make different assumptions to provide the diver with a safe ascent profile. And for the most part, all currently available commercial dive computers do just that. But it's not because one is closer to "correct" than the other. That was my point.

Yes, depth and time are objective facts, and independent of model or algorithm. But we don't carry dive computers to measure depth and time, that's what bottom timers do. We carry them to give us ascent information.

Fair enough. But, "you're gonna die" was really implied by someone else when they told antman that, with his number of dives, he shouldn't carry 2 computers. At least, that's how I took "I wouldn't complicate things by carrying two dive computers." It's one more complicated before you get in. It's really not any more complicated after you get in. If you're really worried about it, you could suggest that he stow the extra computer in a pocket of his suit or BCD, so he can't even see it during the dive.

Eh, I was just responding to that old "show me one dive accident caused by X" thing. You are such a rightfighter. But a smart one, so it's fun to spar with you...

 

[BoltSnap]

The zoop does nitrox. As for the aqualung i think i will sell it. The consensus seems to be i dont need a 2nd and if i do it should be same make as my primary

I would keep the AL over the Zoop or any Suunto for sure. The AL is more "liberal" that you can make more conservative but the Zoop is very conservative that you can only make even more conservative. The Zoop will get progressively conservative/very limiting as you get further into your multi-day multi-dive dive vacation.

There is no consensus regarding having a backup computer at all, in fact, it is the other way around. You want to take 3 - 4 dives a years where the cost of one diving day will far exceed the cost of the additional computer if you stop diving due to a computer going down for any reason. The greater majority of people I know that are frequent dive vacation travelers own at least two computers.

 

[KenGordon]

The zoop does nitrox. As for the aqualung i think i will sell it. The consensus seems to be i dont need a 2nd and if i do it should be same make as my primary

By more than one gas I mean two gases which you can switch between in the water, rather than changing the gas mix at the surface. That feature is about the only functional (ignoring cosmetics like screen type) difference between an entry level computer such as the ones you have and any computer you will ever need. That is used for doing more serious deco dives where a redundant computer, or at least depth gauge and timer, is really required. Until then one computer is enough.

I dive with either two different makes of computer or with two of the same make set to different conservatism or mix. It is not hard, you just stay long enough for both to clear. For NDL dives I have one set for whatever gas my buddy is diving and one for whatever I am on.

Have you got in the sea yet? We are out on Channel Diver on the 23rd. Steve still has some spaces I think. It is due to be a 20m wreck, the Pentrych. See Individuals Dive List, Midweek Diving

A slightly annoyingly early start though...

 

[Centrals]

Computer failure is NOT that rare! It had happened to me twice while underwater and I had seen it happened to another diver on liveaboard. I bailed him out with my back up because the boat did not have any left for rental.

I used to dive with two computers with same algorithms unfortunately one of them expired couple of yrs ago. And the replacement is more liberal but I just follow the data given by the conservative one.

 

[doctormike]

Computer failure is NOT that rare!.

Doctormike recommends the fine Shearwater brand dive computers. Made with Canadian persnicketiness! Extra readable too...

 

[Centrals]

Doctormike recommends the fine Shearwater brand dive computers. Made with Canadian persnicketiness! Extra readable too...

Are you suggesting that Shearwater never fail? I was not born yesterday mate.
If I have $800 to spend on computer I would rather buy two cheapie and save the rest for diving or ticket.

 

[doctormike]

Are you suggesting that Shearwater never fail? I was not born yesterday mate.
If I have $800 to spend on computer I would rather buy two cheapie and save the rest for diving or ticket.

Did I say that they never fail?

 

[Steve_C]

I avoid all discussions about religion.

When I see the words backplate, petrel, or shearwater I start looking for the worn bible. Not saying that they do not have their good points but they have their zealots.

 

[Centrals]

Did I say that they never fail?

I am glad to know that the fine Shearwater band computer do fail. So I can kick them to touch and stick with my ageing 19yrs old Uwatec Aladin.
BTW, any Shearwater computer has celebrated its 10 yr birthday yet?

 

[doctormike]

Yeah, fine. Get whatever computer you like. They are all the same. In the words of the most helpful piece of advice, given out on SB every day, "it's all just personal preference".