In Maine, they come through the fog at 20 knots - I can't see them but they show up on radar. I know they can't hear my fog signals. My solution is just to stay in port.
Favorite has the be the guy in the Cigarette boat (maybe a Formula), leaving Clinton for W Haven. Clears the harbor, goes to autopilot, then goes below for 'something' - just in time to run up on Kelsey breakwater. At least he didn't hit someone else.
It's scary out there...