The curious case of AI. Do you use a back up SPG while using AI?

[Feye]

Can I ask in what way did the transmitter fail?

Thanks for sharing PatW!

On a boat trip, I embarked on three dives, and nobody had AA batteries. The first dive proceeded without any issues, but starting from the second dive, my Perdix gone. (Fortunately, I had a backup dive computer.) It was only upon our return that I replaced the battery, and then the Perdix resumed its normal operation. Straightforward low battery problem.

 

[amado_sarhan]

SPG all the way.

I prefer not to rely on wireless technology underwater but I will grant it has become more reliable.

I am reluctant to invest the money in a primary and backup AI system.

After 30 years, I have a pretty good handle on gas consumption and verifying my SPG is second nature.

No judgment on anyone else's personal preferences.

That was my line of thought. SPGs have been absolutely reliable for me, although I did witness some serious underwater failures on other divers. Because it never happened to me in 20 years of diving, I can't help but think that they were not well maintained. My SPGs are are quite ancient.

I was quite skeptical and had some difficulties adjusting mentally when I tried AI on a rec dive, but I was able very quickly see the added benefits.

 

[rjack321]

Just SPGs. I am not really motivated to spend silly amounts of money on a new computer and multiple transmitters. I have a couple dozen regulators

 

[Tom_Ivan]

I would be keen on being able to look at how my SAC rate differs during a dive. However I have better things to spend my money on at this stage.

SPG's are low cost and reliable enough. They'll do for the foreseeable future.

 

[steinbil]

I've lost 4 HP hoses in the last year and only 1 transmitter failure. That's almost enough HP hoses to pay for a transmitter. My standard config is side mount with transmitters and gauges on all stages and deco bottles.

That sounds like a lot of hose failures. Which brings me to 3 questions:

1) Miflex or rubber?
2) How many dives?
3) Are they bent like SPGs on a stage?

Edit:
And 4) Were they all old hoses that just happened to all die in the same year, or are they around a year old?

 

[amado_sarhan]

Just SPGs. I am not really motivated to spend silly amounts of money on a new computer and multiple transmitters. I have a couple dozen regulators

Fair enough. Cost is an important factor. Especially that AI remains a convenience, not a neccesity.

 

[OMyMyOHellYes]

No judgment on anyone else's personal preferences.

You DO understand that this is SCUBABOARD, right ?!?

 

[Divin'Papaw]

One question that I have found very illuminating to this debate is the following:

Prior to using an AI computer, how many SPGs did you use on your kit? Given that the answer is almost certainly one, why do you feel the need for redundancy now? If one "pressure measuring device" was sufficient before, why are two now required?​

That is the question that really got me to drop my SPG. Given that, in my personal experience, AI had been just as rock-solid dependable as my SPG had been, why was I carrying two pressure measuring devices? I couldn't come up with an answer for myself that made sense.

Just something to ponder. I don't consider it wrong, stupid, or foolish to carry an SPG along with an AI computer. Not in the least. Do what you are most comfortable with. But the above question, for me, was very illuminating in my own personal decision making.

 

[amado_sarhan]

One question that I have found very illuminating to this debate is the following:

Prior to using an AI computer, how many SPGs did you use on your kit? Given that the answer is almost certainly one, why do you feel the need for redundancy now? If one "pressure measuring device" was sufficient before, why are two now required?​

That is the question that really got me to drop my SPG. Given that, in my personal experience, AI had been just as rock-solid dependable as my SPG had been, why was I carrying two pressure measuring devices? I couldn't come up with an answer for myself that made sense.

Just something to ponder. I don't consider it wrong, stupid, or foolish to carry an SPG along with an AI computer. Not in the least. Do what you are most comfortable with. But the above question, for me, was very illuminating in my own personal decision making.

I find your reasoning very sound.

 

[KenE]

One question that I have found very illuminating to this debate is the following:

Prior to using an AI computer, how many SPGs did you use on your kit? Given that the answer is almost certainly one, why do you feel the need for redundancy now? If one "pressure measuring device" was sufficient before, why are two now required?​

That is the question that really got me to drop my SPG. Given that, in my personal experience, AI had been just as rock-solid dependable as my SPG had been, why was I carrying two pressure measuring devices? I couldn't come up with an answer for myself that made sense.

Just something to ponder. I don't consider it wrong, stupid, or foolish to carry an SPG along with an AI computer. Not in the least. Do what you are most comfortable with. But the above question, for me, was very illuminating in my own personal decision making.

I have thought about the same thing and my answer was different from yours. I see the biggest difference is the battery. Although the SPG has a lifespan, it is nowhere as short as that of the battery. Yes, I can abort a dive if battery fails, but having an spg next to my inflator saves that dive, why not have it there? So, I have not removed my SPG from the kit. I have since changed to a new computer and transmitter and looking at battery life monitoring. Maybe this will change. My last computer did not show the transmitter battery status, so failure or premature replacement was the only options. I had a good battery replacement process, but one battery did not last like the others. SPG allowed us to continue the dive and replace battery at SI.