Just purchased my own equipment I picked up 2 Smart Z's new and reasonably priced. Do I need gauges as a back up? Are they required by dive charters? Should I just buy a pressure gauge or get the whole setup including a compass. Pretty new to diving so be gentle!!!
As an Instructor when diving with an Air Intregrated Dive computer I do not carry an analog backup. Here is my thought on this:
If your air integrated Dive Computer fails as in complete shutoff you will have no means to track your no decompression time or your no stop time. Therefore unless you are wearing a backup time piece and depth gauge and have either reviewed your dive tables before the dive or have water proof dive tables on you if would be very difficult to proceed with the dive safely.
If the wireless transmitter fails but the rest of your dive computer remains function the above situation would not apply.
But in either case I would call the dive and head back to the boat. Reason being unless you are extremely familiar with the workings of the Smart Z and know without a shadow of a doubt that it would continue to provide you with accurate dive/deco information you could be putting yourself in a dangerous position.
Some divers would argue to use their buddies dive computer as backup and continue the dive. People do this on a regular basis but can be dangerous also unless the 2 divers have exactly the same profile. Any thing else is S.W.A.G.
Scienctific Wise A_ _ Guessing
Just my 2 cents
Hope this helps.