Crests with glassy appearance, but do not break. Glassy looking foam, occasional white horses. Many white horses, some spray. 6 Strong breeze Some large waves, extensive white foam crests, some spray. Gale Moderately high and long waves.
Crests break into spin drift, blowing foam in well marked streaks.
Spray reduces visibility. Storm Very high waves with long overhanging crests. Dense blowing foam, sea surface appears white. Heavy tumbling of sea, shock-like, poor visibility. Sea completely covered with long white patches of foam.