I’ve lived here 30 yrs and have only seen this phenomenon 3 times including today. It is absolutely bizarre and is the inspiration for the Stephen king movie. It happens when the air is unusually warm (83 today) and the water very cold. It’s not Your typical fog by far. It’s much denser. Visibility is about 6 feet. From a distance it looks like a blanket laying on the ocean. And as you approach it it looks like a wall. It also drenches you as the moisture content is so high. Incredible sight. It’s like a sci fi movie.