Why the concern? I'm guessing you're a recreational diver and you said this is a backup computer.
The principal thing you need the computer for is for how much NDL time remains if your primary craps out. Metric/imperial units are a big don't care. . .
The principal thing you need the computer for is for how much NDL time remains if your primary craps out. Metric/imperial units are a big don't care. . .