Question when using hoseless air

[Puffer Fish]

If you continue to use an SPG with a wireless transmitter, what is the point since checking an SPG is about as quick as checking a wrist dive computer? Redundancy? Why not put an SPG attached to a hose in your save a dive just in case you have a failure and leave it off the reg?

Reasonable question to ask.

First off, there is a difference between doing a couple hundred dives with one and doing a thousand.

I dive with a backup computer also (ok, is a wristwatch one, but still a backup). And yes, I could just have one in my save a dive kit...except at some locations, your save a dive kit will not be on the boat (Heron island comes to mind), so you will miss the whole trip (ok, "only" two dives, but two expensive dives).

I use an integrated computer to keep track of gas used during a dive and for multigas dives. If you don't go wireless, then you will not have any backup (or a mess of hoses if you try).

Understand the desire to have a simple setup and if you don't care if you miss dives, that would be reasonable.

I have a pony spg and transmitter on my deco bottle, and an spg with a transmitter on my main...but where and how you dive is not the same for everyone.

 

[Straegen]

If a diver uses a standard brass and glass SPG and a dive computer, aren't they at the same risk or in those situations or do they run with two SPGs? I never considered running with two SPGs, but I do keep an extra gauge and hose in my save a dive kit. What is the fail rate of an xmitter compared to a brass and glass?

I was thinking of switching just to streamline but if I still "need" an SPG doesn't make much sense given that I dive strictly recreational.

 

[jd950]

If a diver uses a standard brass and glass SPG and a dive computer, aren't they at the same risk or in those situations or do they run with two SPGs?

If I understand your question correctly, yes. I have noticed before that while many say one should have a backup spg when using a hoseless computer, few people advocate carrying two SPGs.

The explanation for this is usually the claimed unreliability of the computer vs. the supposed bulletproof nature of the SPG. Yet, I have had an SPG fail and been present on two occasions when HP hoses have burst (rendering the SPG useless and of course, causing a loss of air) and have seen plenty of reports of failed SPGs. I have yet to experience a significant computer failure, although I know they happen.

The decision to carry a redundant computer or SPG is a personal one. Each of us should do what makes us feel good. I dive with a backup computer, but it isn't AI. I keep a backup SPG in my gear, but don't take it on the boat. Under some circumstances, I might change this. In the meantime, I suppose I could lose part of a dive day due to a computer failure, but the same could also happen to anyone diving a single SPG.