Had a friend die in a boat accident both him and the operator were drinking.

They still do it here. Maybe spying on you from a distance may be considered fair game because they could claim they were looking for wildlife violations. I don't know.
They also sit across the bay from a waterfront bar and stop boats leaving the docks at the bar. One thing of note however is maritime law states that you can be stopped anytime for no reason unlike doing a normal traffic stop on a roadway which must have cause. Again , I don't know. I've never gotten a DUI or BWI.