> But both the backup regulator and dice computer is on your companion. You don’t dive with two yourself. You're entirely welcome to have backups. I dive with

> But both the backup regulator and dice computer is on your companion. You don’t dive with two yourself. You're entirely welcome to have backups. I dive with 2 lights, and if the Apple Watch didn't require a subscription I'd gladly buy it to also dive with 2 computers. My divemaster had a second bottle with its own independent octopus for cave diving. Anything you can afford to double (both financially and in terms of practicality/weight/encumbrance), by all means, go ahead and do it. Triple it if makes sense.