Belzelbub
Contributor
Same here. That doesn’t really make sense. If the reason is redundancy, I wonder how many divers are running two SPGs off of a single first stage.I never did see the sense in buying and using AI while carry a SPG for backup.
Both SPGs and *transmitters are very reliable. So, for most recreational dives, carrying a backup SPG or transmitter is just not required. In either case, it woul be a good idea to carry a backup pressure reading device in your save a dive kit.
*Some transmitter types are more reliable than others. PPS are probably the simplest, and seem to have the fewest complaints. They turn on with pressure and that’s it. Other types use power saving features that are pretty much unnecessary and add complexity and opportunities for things to go wrong.