Fog

In maritime law

Any atmospheric condition (including not only fog properly se called, but also mist or falling snow) which thickens the air, obstructs the view, and so increases the perils of navigation.

Flint & P. M. R. Co., v. Marine Ins. Co. (O. Ct) 71 Fed. 210; Dolner v. The Monticello, 7 Fed. Cas. 859.