Computer and Backup Configuration for Rec Diver?

[Nemrod]

Along with several others, I rarely check my spg during a dive. I look at it about mid dive and then towards the end. Yes, and on the boat, lol, I breath off my reg to make sure the needle does not drop before I drop in! I find AI to be a complication and unnecessary. I am a minimalist diver and the spg is proven and reliable, it is all I need or want.

At only 61 the OP could have 20 or even 30 years of diving ahead of him. I know of divers in their 90s. Why all the doom and gloom? Nobody gets out alive but he could have many years of diving adventures yet to go. Therefore he should buy whatever equipment makes him happy.

If you want AI, get it and keep the Peregrine as back up. Having two computers can be useful on a long vacation trip, has been for me more than once. But, I specifically bought the Peregrine because it was NOT AI and I prefer my old fashioned compass as well.

I quite like aluminum 63s and 80s and both have enough gas to get me into deco at even moderate depths and are ubiquitous through the Carib. Once a diver settles down and gets some experience, they should be able to guesstimate their gas remaining by just noting their dive time. Which is why I still wear a watch, but of course a dive computer, with some button pushing, gives the same info, more or less.

James

 

[inquis]

who need a back-up computer for rec dives

Its not needed on that dive, but might be needed on the next. It's basically trip insurance to avoid changing plans.

I would pick option 2.

 

[tursiops]

I take the cost of the item and divide it by the number of years I expect to be dead.

?? I expect to be dead for an infinite number of years, so the result of the calcuation will always be zero.
Perhaps you mean the number of years left before I expect to be dead?

Door #2, but without bothering with the SPG on a hose; I have a lot of faith in the AI, and will surface if the AI fails.

 

[boulderjohn]

?? I expect to be dead for an infinite number of years, so the result of the calcuation will always be zero.
Perhaps you mean the number of years left before I expect to be dead?

Door #2, but without bothering with the SPG on a hose; I have a lot of faith in the AI, and will surface if the AI fails.

I meant what I wrote, and your math is correct.

 

[scubadada]

I am mainly a recreational diver, about 5% of my dives are light deco. I am 67 years old.

I have been diving a primary computer with AI for a little over 11 years, 1626 dives. I have been diving a backup computer and a backup SPG during this time. I have needed a backup computer for just 2 dives, 0.12%, when I let the battery on my primary computer go dead. I have needed a backup SPG on 12 dives, 0.74%, These include the 2 dives above, 2 dives with a dead transmitter battery, 5 dives with a transmitter failure, 2 dives when I forgot to install the transmitter in a different reg set, and 1 dive when I used a loaner reg set because of a 1st stage failure on mine. So, the two dives for which I needed a backup computer, and 6 of the 12 times I needed a backup SPG, were entirely my fault. Six of the dives for which I needed a backup SPG were due to equipment failure.

So, for the last 2 1/2 years, my backup computer has also been AI, a Teric, running off the same transmitter as my trusty old Oceanic VT3. Unfortunately, my Terics have not been perfectly reliable and I have had 3 failures during dives, one black screen and loss of AI twice. I am still diving a SPG Teric owners, have you required repair or replacement service? If I were diving the Teric alone, I would have missed a number of dives.

I'm loathe to miss dives or parts of dives. My gear configuration has allowed me to avoid that. To each their own. I dive with an analog compass too

 

[Hoag]

Ok, playing the Devil advocate, I dare to ask: who need a back-up computer for rec dives
As for AI, what is the point? Don't you (general "you")know your approximate consumption and is to watch the gauge 4 or 5 dives during the dive, a difficult task?
Keep the easier one to read for yourself and give the other to your daughter.

I am a recreational diver. I would even go as far as to say that I am a vacation diver. Please allow me to address your questions.

First, with regards to why a rec diver would need a back-up computer, a couple years ago, I was on a LOB, and my computer failed. Luckily, the boat had a spare which they were kind enough to lend me for the rest of the week. If they didn't, then I would have had no computer and would have been done diving for the week. Having a Back-up or a redundancy is never a bad idea. When I got home, I bought a computer that I could use as a back up. As the saying goes, "Two is one, and one is zero."

Second, with regards to AI, I don't understand your issue with a recreational diver having AI. It just makes sense to have your information located on the same device. A diver can look at their AI computer and can check all relevant information. Doing it any other way is simply not efficient. Many (most???) AI computers also display both NDL and some variation of GTR, so the diver constantly knows whether their dive will be limited by NDL or by GTR and how long they have before they have to end the dive.

I don't imagine for a second that I have convinced you, but that is OK. We are both entitled to our opinions.

 

[wetb4igetinthewater]

Luckily, the boat had a spare which they were kind enough to lend me for the rest of the week.

The only problem with the spare is that it had no idea about your residual nitrogen. While there is some risk due to this, there are ways to deal with it that while fall under normalization of deviance, but understandable given the time/expense/rarity of being on a liveaboard.

 

[Hoag]

The only problem with the spare is that it had no idea about your residual nitrogen. While there is some risk due to this, there are ways to deal with it that while fall under normalization of deviance, but understandable given the time/expense/rarity of being on a liveaboard.

I wasn't too worried about residual N2. My computer failed on descent on the first dive of the morning and I had been out of the water since about 4pm the day before. Yes, there was some residual N2, but I think it would be fairly low.

 

[Wibble]

I wasn't too worried about residual N2. My computer failed on descent on the first dive of the morning and I had been out of the water since about 4pm the day before. Yes, there was some residual N2, but I think it would be fairly low.

Which is why you dive with your spare. And should the primary die during a dive, oh, you have a spare on the other wrist.

 

[Hoag]

Which is why you dive with your spare. And should the primary die during a dive, oh, you have a spare on the other wrist.

Yup. It was after this trip that I got a spare & started diving with it.

Someone asked in an earlier post why a recreational diver would need a spare, so I explained why I dive with one.