With ClearNav you can use the Amoebas as a good way of verifying ridge clearance. Set one amoeba to zero and the other to 1000 ft. Using the Amoebas for the ridge problem, allows the more sensible: reserve = 0 setting. Using the amoeba this way gives a visual / analog sense of clearance that is really better than a go/ no go. The width of the amoeba clearance through the pass or over the ridge provides a great indication of margin.