I'm a King Air Captain and I've experienced the famous ACK fog. It is amazing to pilots who has never experienced that kind of sea fog. I arrived an hour before our scheduled departure on a beautiful evening, with not a cloud in the sky. Then within the hour, this strange mist began to move in. Before you know it, you couldn't even see the next plane beside you parked on the ramp. I've never experienced that before. It was something.