Whitby, August 8

I've been reading Dracula, and there is this part in which a ship arrives in the middle of the storm, with the sails fully open and just a dead body tied to the wheel, with a cross in his hands. I tought it was awesome, and drew it while i ate dinner xD I suck at doing backgrounds and at coloring.. so it is supposed to be a boat in the middle of the wild sea at night. I wanted to make it look like the light of a lighting, but i figured out i didnt know how to do that.. so you just get lame shadowing and mist, or fog.. what's the difference between mist and fog?