Which has a higher rate of failure a SPG or a transmitter?

[diveprof]

I do not use AI computers. I've been on no less than 3 dives this past year where AIs have lost signal that required resurfacing to sync or permanently failed. Expensive models too. About 3000 dives and I've never had an issue with a SPG. Me, I need a computer that does nitrox. Beyond that, I'd rather spend the money on diving. If you AI computer fails you do not know how much air you have left. Dive over, maybe dive trip if you cannot get a rental. I dive with a nitrox non AI console computer and wrist computer and an SPG. If one of my computers dies, I have a second computer and a SPG so the dive is not over and there is minimal impact on my trip. You can buy 2 non-AI computers for the price of 1 AI computer. My 2.3 cents (inflation you know).

 

[dmoore19]

I would guess that the failure rate of the transmitter has dropped substantially as the technology has developed. I would guess that the first SPGs were not very dependable either. Probably as much discussion between divers using the SPG when it first came out and the ones that didn't like it because they had a J valve and the SPG could fail.

This question is for single tank recreational dives only. Does anybody have 2 SPGs in case one fails? I don't see a huge problem here, you don't even have to have any special training to ascend without an SPG

I wouldn't go on a once in a lifetime dive trip without having first put new battery in the computer and the transmitter and making sure it worked. Changing a battery prior to a trip would be cheap insurance and part of proper maintenance IMO.

I would also think that an issue with syncing has greatly decreased since the technology was introduced. I make sure mine is synced before I enter the water. I have to turn the computer on to do this to make sure the tank has the pressure it should and to check that the valve is fully open.

I would guess a large percentage of the failures seen are operator error. I think it is great technology. If you see it as too expensive, don't buy it.

Unfortunately unless someone has data to prove one way or the other it is strictly personal opinion.

 

[diveprof]

I would guess that the failure rate of the transmitter has dropped substantially as the technology has developed. I would guess that the first SPGs were not very dependable either.

I wouldn't go on a once in a lifetime dive trip without having first put new battery in the computer and the transmitter and making sure it worked. Changing a battery prior to a trip would be cheap insurance and part of proper maintenance IMO.

I would also think that an issue with syncing has greatly decreased since the technology was introduced. I make sure mine is synced before I enter the water. I have to turn the computer on to do this to make sure the tank has the pressure it should and to check that the valve is fully open.

I would guess a large percentage of the failures seen are operator error.

Unfortunately unless someone has data to prove one way or the other it is strictly personal opinion.

You are correct that what I've stated are just my observations - my comments are not formal research. Most of what is on SB is opinion. However, to further clarify. All three AI computers that failed were new, less than 1 year old and were not battery issues. One flooded and two lost signal with one of those resulting in a cancelled dive because it would not re-sync even after surfacing and trying to re-sync. I just don't want to go there and don't recommend it. You suggest that problems have dropped with development of technology. I would like to see the comparison of durability and functionality of dive computers of several years ago vs the current crop. Most dive computers and /or major components are made off shore now (China, etc). Personally, I think quality has slipped a bit (again opinion). Newer computers have more whistles and bells, but I'm not so sure about durability. That's why I dive two.

 

[scubadada]

I have been on a few dives where people transmitters would not link up. Three where batteries failed. My SPG only failed once and it was on rental gear. I cannot see giving up my analog gauge. Especially when these integrated computers cost what they do. And if they are so great why are trimix comps not using the technology. Shearwater, Liquivision, VR tech, etc. None of them use transmitters. And those are the only kinds of computers I'd pay more than say 500 bucks for. Heart Monitor? dumb.

Hi Jim,

Liquivison Lynx has a transmitter, don't be an elitist snob

Two years with an Oceanic VT3, not a single problem.

I agree, no heart rate monitor for me.

Best, Craig

 

[kimbalabala]

Our personal experience - my husband's Oceanic HUD wouldn't link up so he sent it back, and they sent it back and it still doesn't work (still working on getting that resolved). For our recent trip to the Keys he decided to get an inexpensive spg and use it alongside his Cobra AND Gekko - and believe it or not, his COBRA DIED!! Turns out he's a genius and that little spg saved the day!!

 

[dmoore19]

You are correct that what I've stated are just my observations - my comments are not formal research. Most of what is on SB is opinion. However, to further clarify. All three AI computers that failed were new, less than 1 year old and were not battery issues. One flooded and two lost signal with one of those resulting in a cancelled dive because it would not re-sync even after surfacing and trying to re-sync. I just don't want to go there and don't recommend it. You suggest that problems have dropped with development of technology. I would like to see the comparison of durability and functionality of dive computers of several years ago vs the current crop. Most dive computers and /or major components are made off shore now (China, etc). Personally, I think quality has slipped a bit (again opinion). Newer computers have more whistles and bells, but I'm not so sure about durability. That's why I dive two.

Electronics are funny things. Few of the parts are manufactured in the US and the same can be said for assembly. Seems like it has been that way for a long time. Remember when the cheap stuff came from Japan? I do dive with a backup computer. Not because I am afraid of my main computer failing but if it did it could put a damper on the whole trip, not just 1 dive. I also have a SPG that comes with me, I just keep it in the save a dive kit. I know my dive count is much lower than yours and you have the experience over me. I will say that I have never once seen anybody on any of my dives have a computer, SPG or hose fail. I have seen a few busted fin straps, mask straps and tank o-rings. I carry spares of those even though I have spring straps and flap strap for myself. I have saved other peoples dives with this small stash. I don't dive tech and I don't dive deco. I am too old for that stuff. That said, anything can fail at any time.

 

[diveprof]

It really would be interesting to have hard failure rate info on AI vs non-AI computers. However, I doubt that the scuba equipment manufacturers would want that knowledge published. The best we have is personal observation. I've seen enough for me. Not that I think having an AI computer is "wrong," they are convenient and have lots of whistles and bells. However, I'd want a backup computer and SPG.

 

[rongoodman]

I thought SPGs were pretty bombproof until I broke not one, but two, on my last trip. The only thing I can think of was being clumsy clipping and unclipping stage/deco bottles underneath sidemount tanks. Next year I'll take a spare, and try to be more careful!

 

[Centrals]

Never had an issue with an spg in any of my recreational and baby technical dives.
My non AI computer failed once under water and I just followed the dm and stayed above him all the time. Called off the 2nd dive.
Nowadays, I dive with a computer, a bottom timer + spg.
Two computers should be about right so you do not miss the 2nd dive if your only computer failed on the 1st dive.

BTW, I just do not like the idea of putting all the eggs in one basket.

 

[Blue Sparkle]

In today's world of diving, which has a higher rate of failure a SPG or a transmitter?

Both of these tools can fail, but which one fails
more often. Our experience is the Old reliable SPG.

However, our repair dept. has more problems with the SPG's that we service than transmitters.

I have a question for you: Have you sold equal numbers of both?

I ask because if there are 1000 SPG's out there, and 250 transmitters, then even if you have twice as many SPG's failing as transmitters, that would still be a higher failure rate for transmitters.

Without knowing the total numbers we can't tell, but I suspect there are (at this point) many, many more SPG's out there, so I don't see "more coming in with problems" necessarily being meaningful.

On the other hand, if you do have those numbers (and we are comparing the same number of each), but just didn't put them in your post, then could you? That would make it meaningful.

I only have one comparison: One of each. My dive buddy bought a new AI wrist computer at the same time as I bought a brass-and-glass SPG. We took the same good care of both of our gear. Less than a year later, he had been through two different AI replacements, I had no problems.

That's only anecdotal and with an extremely small sample size. But we do know it's a one-to-one ratio, SPG to AI.

One last comment is that I believe it's easier to carry spare SPG's (since we know either type CAN fail). For one thing, they are interchangeable between rigs and divers (i.e. not proprietary - are the transmitters the same across brands?), and also they are less expensive to stock as spares (as compared to a wrist unit-plus-transmitter). Similarly for an HP hose vs. an AI wrist-unit-plus-transmitter.

Blue Sparkle

PS: What sort of failure rate have you had for the wrist units themselves? If I remember correctly, one of my buddy's failures was the wrist unit and the other was the transmitter, but I'm not sure about that.