It is interesting to me that divers will carry a redundant pressure guage in order to ensure that they do not get low fills or to avoid ending a dive prematurely in event of AI failure. I think the answers to the question only makes sense when one has a feel for the particular diver's outlook.
For example, I travel internationally to dive every month so I have a lot of instabuddies whom I may not nescssarily want to rely on, therefore I carry redundancies as a self reliant diver. I also love diving in mask ripping currents and carry multiple signalling devices in the event of boat seperation. In other words, I carry a lot of equipment that I prioritise over a redundant pressure guage. To me, a spare mask (prescription lenses) is more important than a redundant pressure guage because, although I am very comfortable in the water without a mask, should I ever lose a mask in a current I will need the spare mask to see my computer if only to ascend safely. The list of equipment that I prioritise over a redundant pressure guage and carry on all dives include:
- spare mask (prescription lense)
- pony
- torch (two on a night dive)
- signal mirror
- smb & reel
- air horn
- nautilus marine rescue
- PLB and canister (carried in more remote areas)
- knife
- line cutter
- 2 dive computers
Whilst I can understandand the redundancy offered by a redundant pressure guage, to me it is very much a non-essential rdundancy.
I wonder what other equipment is carried by the divers who choose to carry a redundant pressure guage.