adjacent to ice mass ice lead 2019-02-27T19:26:14Z Generally, leads are wide enough (and deep enough) for navigation by surface vessels. The term is generally applied to linear features. If the open area is very large it may be called a polynya, although the application of these terms is under debate. A surface layer of a water body which has been formed as the result of surface ice fracturing and moving apart. lead http://sweetontology.net/realmCryo/Lead envoPolar surface layer of a water body