For most tool watches the requirements are pretty clear-cut. A dive watch needs to survive meters of water pressure. A racer's chronograph needs to have the ability to record time.
A pilot's GMT should keep a second time zone. But a tactical watch? There are no real clear-cut rules— many watches can handle an outdoor excursion but few are made specifically for the job.,For most tool watches the requirements are pretty clear-cut. A dive watch needs to survive meters