Beaufort Scale

Sea like a mirror

Ripples without crests

Small wavelets, glassy crests

Large wavelets, scattered whitecaps

Small waves, frequent whitecaps

Moderate waves, many whitecaps, some spray

Large waves, whitecaps everywhere, more spray

Sea heaps up, foam blown in streaks

Moderately high waves, crests break into spindrift

High waves, dense foam streaks, spray reduces visibility

Very high waves, sea surface largely white, visibility affected

Exceptionally high waves, sea covered with foam patches

Air filled with foam and spray, very poor visibility