Ripples without crests.
Wind motion visible in smoke.
Wind felt on exposed skin.
Large wavelets; leaves and smaller twigs in
Dust and loose paper raised.
Small branches begin to move.
Moderate longer waves; some foam and spray.
Smaller trees sway.
Sea heaps up and foam begins to streak.
Large branches in motion; umbrella use becomes difficult.
Moderately high waves with breaking crests.
Streaks of foam.
Twigs broken from trees.
Cars veer on road.
High waves with dense foam. Wave crests start to roll over.
Light structural damage. Very high waves.
The sea surface is white and there is considerable tumbling.
Visibility is reduced. Trees uprooted.
Considerable structural damage. Huge waves.
Air filled with foam and spray.
Sea completely white with driving spray.
Visibility very greatly reduced.
Massive and widespread damage to structures.
... by Sir Francis Beaufort.