Fog is one of the many dangers lurking for walkers in the bay of Mont-Saint-Michel. Mostly present in autumn or in spring, the fogs on the shores are low and compact, dispersing light and muffling sounds. Compact fogs can suddenly appear and cover the entire bay with a white veil. A walker who has lost their bearings will wander on the foreshore without finding their way. This layer is hardly more than twice the height of a man, but the lower it is, the thicker it will be.