fogdog

fog·dog

F0221800 (fôg′dôg′, -dŏg′, fŏg′-)n. A bright or clear spot that appears in breaking fog.
[From the fact that it accompanies fog as a dog accompanies its owner.]

fogdog

(ˈfɒɡˌdɒɡ) n (General Physics) a whitish spot sometimes seen in fog near the horizon. Also called: seadog