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It's a regulator because of the center minute hand. I am under the impression that it is was initially a dive complication. While diving, hours and seconds don't truly matter, therefore having minutes as the primary form of time on the dial makes it easier to read at a glance under water.
Oris released a regulator with their Aquis line recently which I found pretty cool.
It's a jump hour. The window @ the 12 is the hour , not a date complication , therefore a jump hour.
Definitely not a dive watch