I’ve experienced the ‘surprise!’ fog on exiting the Hindhead Tunnel northbound (frequent cause of those sirens I mentioned previously. Funny how I know there might be fog there at any time but the daily commuters don’t. Perhaps they never took the A3 before the tunnel so don’t know from experience that Hindhead has its own micro-climate?), but ‘serious’ fog from the sea is something I have yet to fully experience. Closest I have come to it is on a visit to Highcliffe, where it was lovely and sunny on the mainland but the IOW had disappeared in sea fog. We sat in the sunshine eating ice cream, listening to the sound of the fog horn on Needles lighthouse.