Hoseless computer alone or with backup

[Centrals]

1. No hoseless computer.
2. Dive with either two computers or one computer + one BT.
3. Analogue spg clip off left chest D-ring. And I check the reading regularly. If it fails then it is time to go up.

 

[sphyrnidus]

1. I dive with a hoseless computer
2. On trips I take a spare computer, otherwise not
3. Analogue spg clipped in "dir" style to left hip D-r ring
My hoseless computer only tells me how much gas I have, once I'm in the water. I want to know how much gas there is in the cilinder before I jump in to the ocean. That's why I added the spg.

 

[Oldbear]

Murphy's law dictates that you will never have any issues with your AI dive computer diving where it is convenient to service...e.g. close to home. The law is exercised when you are on a Liveaboard that you paid $1000s for in some remote part of the world where your batteries will fail. I am speaking from experience.

I NOW dive with a SPG or in-line computer and a wrist mounted AI dive computer for convenience...redundancy is a good thing, reliability is even better.

 

[doctormike]

My hoseless computer only tells me how much gas I have, once I'm in the water. I want to know how much gas there is in the cilinder before I jump in to the ocean. That's why I added the spg.

Really? I never heard of a computer that you couldn't turn on on the surface... what model is that? How do you set it?

 

[scubadada]

Dear friends:
I am curious what folks who have a hoseless dive computer do on a dive with respect to also carrying a spg or not?
Thank you

I dive an Oceanic VT3 primary and a Geo2 with a SPG as backup. I've had the VT3 4 years, 414 dives with no problems. I've not needed the backup but am glad I have it, especially on multiday, multidive dive trips.

 

[freewillie]

I won't argue the fact a back up SPG is easy enough to use just in case. But it only tells you how much air you have left. You should have a fairly good idea of that anyways if you are checking your air often and frequently. How do you tell your depth at that point and would you continue your dive without then being able to track the bottom time. Without knowing either the depth or bottom times you won't be able to plug those numbers in on dive tables for your pressure group anyways (assuming you have an old fashioned table since the computer is now not working.) Your dive should be ending anyways if your computer goes out.

Personally I've also never thought the logic makes sense to purchase a $1000 piece of electronics then thinking what happens if it fails. For a that much money it better not fail! The only reason it should not behave properly is if I as the brain dead diver forgets to change the battery or worse don't close the back and it floods. Either way that's my fault, not the computer. Once I actually save enough to buy the AI wireless wrist computer the SPG will go in my spare box. If I did spend the money for a week's diving vacation I'd probably buy a $300 back up computer or just make sure I have new batteries.

 

[Banyan]

The only reason it should not behave properly is if I as the brain dead diver forgets to change the battery or worse don't close the back and it floods. Either way that's my fault, not the computer.

Sheepishly raises hand.

After I bought a wireless computer, I never got around to removing the SPG. I also procrastinated about replacing the battery on my computer, despite the warning coming on. Then in the middle of a dive, my computer died. This was on a shore dive that I'd done about 20 times where you had to dig to get below 45 feet, so there was zero risk, but I decided then to keep the SPG (now clipped to my left hip D-ring) and pay more attention to low battery warnings. I like to think I'm a better diver now, but I certainly appreciate the redundancy.

 

[dallaskincaid]

My hoseless computer only tells me how much gas I have, once I'm in the water. I want to know how much gas there is in the cilinder before I jump in to the ocean. That's why I added the spg.

I think I'd get a new dive computer.

 

[doctormike]

Personally I've also never thought the logic makes sense to purchase a $1000 piece of electronics then thinking what happens if it fails. For a that much money it better not fail! The only reason it should not behave properly is if I as the brain dead diver forgets to change the battery or worse don't close the back and it floods. Either way that's my fault, not the computer. Once I actually save enough to buy the AI wireless wrist computer the SPG will go in my spare box. If I did spend the money for a week's diving vacation I'd probably buy a $300 back up computer or just make sure I have new batteries.

That's not true. Dive computers themselves are fairly robust pieces of equipment. Wireless air integration, on the other hand, is not. It is certainly possible for the WAI to fail without the computer failing. In my experience this happens on occasion, with fully charged batteries, and no leak.

As I said upthread, IMHO the best solution is an SPG clipped to your waist and a dive computer on your wrist.

 

[KenGordon]

I use both AI and a spg on all dives. I use the spg on the dive, it is easier to read, my buddy can look at it and it is basically fail proof. The computer lets me download my air consumption which is very informative.

When I first had it I found I would often get the syncing wrong by some means and have no reading for a whole dive. Now it (or my usage) seems to have settled down - no need to sync usually - and it mostly works. However, is does drop out of a while now and again so I would never be tempted to use it as my only source of information.

Talking of computer failure, batteries don't like the cold, a computer with a marginal battery might be fine on the surface but give up at depth when you get to the cold stuff.