As well as clothing, make sure you have a good thermos (one that will stay hot overnight). Cuppa soups, and cuppa noodles are good. (oops pressed send by mistake). As for the fog, I've been sitting there and have it roll in at about 10pm, couldn't see the front of the boat, and ended up staying until 7:00am when it cleared enough to be safe. Thickest fog I've ever seen and I wasn't planning on staying overnight but luckily I always go prepared just incase so I had plenty of clothes and food. Still got bloody freezing though even with thermals and all the layers on, so if you're going, be prepared for overnight even if it's not planned.