Definition of Leading Lines/Ranges
A group of two or more marks or lights, in the same vertical plane such that the navigator can follow the leading line on the same bearing.
− Wind speed 56 − 63 kn or 28.5-32.6 m/sec
mean 60kn or 31 m/sec (Exceptionally high waves.)
(Small and medium sized ships might be for a time lost to view behind the waves.) The sea is completely covered with long white patches of foam lying along the direction of the wind. Everywhere the edges of the wave crests are blown into froth. Visiblity affected.)
− Wind speed 48 − 55 kn or 24.5-28.4 m/sec
mean 52kn or 27 m/sec
(Very high waves with long overhanging crests. The resulting foam, in great patches, is blown in dense white streaks along the direction of the wind. On the whole, the surface of the sea takes a white appearence. The tumbling of the sea becomes heavy and shock-like. Visibility affected)