Belzelbub
Contributor
This is a risk that is easily mitigated. The batteries are pretty cheap. I make it a point to change them every year. I've been doing this pretty much since I started diving with wrist mount AI about 10 years ago. Still using that same PPS transmitter.I am in the "both" camp when I dive single-tank, at least for now. The main reason is that the transmitter has a battery. I know that in due course, the battery will get low before it then needs to be replaced altogether. I don't want to make assumptions about how quickly the battery goes from first seeing the red-light to unreliable transmission to finally, dead.
Again, most likely easily mitigated. Biggest risk would be if someone were to use it as a handle to lift gear. That's probably not too common anymore as transmitters are fairly common and boat crews should be aware of them. Some use a short hose to avoid that. Either direct mounted, or on a short hose, the transmitter is out of the way and fairly well protected between BC and tank.There is also the (probably small) probability that the transmitter has an electronics failure or is damaged on the boat. I think it is a little more fragile than an SPG made of tempered glass and steel. In any of these situations, I can continue the dive with no interruptions. If it's dive #1 of a day with 4 or 5 dives planned, I can continue the remaining dives with no inconvenience, and without worrying about whether there is a wrench on the boat.
I keep an SPG in my SAD kit. Along with spare o rings and a wrench to change out if necessary. Never need to worry if one is on the boat, as I brought them with me.