The Beaufort Scale

Force One - Light air (1-3 knots)

Sea state:

Ripples with the appearance of scales are formed but without foam crests.

From land:

Direction of wind shown by smoke drift but not by wind vanes.

Forces-of-Nature sports:

Climbing, gorge walking, downhill mountain-boarding, surfing or stay at home and mend broken kit.

Force Two - Light breeze (4-6 knots)

Sea state:

Small wavelets, still short but more pronounced. Crests have a glassy appearance but do not break.

From land:

Wind felt on the face. Leaves rustle. Ordinary vane moved by wind.

Forces-of-Nature sports:

Climbing, gorge walking, downhill mountain-boarding, kite-flying, surfing or stay at home and mend broken kit.

Force Three - Gentle breeze (7-10 knots)

Sea state:

Large wavelets. Crests begin to break. Foam of glassy appearance. Perhaps scattered white horses.

From land:

Leaves and small twigs in constant motion. Wind extends light flags.

Forces-of-Nature sports

Climbing, gorge walking, downhill mountain-boarding, surfing, kite-flying and kite-buggying.

Force Four - Moderate breeze (11-16 knots)

Sea state:

Small waves becoming longer. Fairly frequent white horses.

From land:

Raises dust and loose paper. Small branches are moved.

Forces-of-Nature sports

Surfing, kite-buggying with medium sized kites, kite-surfing with big kites, windsurfing with big kit.

Force Five - Fresh breeze (17-21 knots)

Sea state:

Moderate waves, taking a more pronounced long form. Many white horses are formed. Chance of some spray.

From land:

Small trees in leaf begin to sway. Crested wavelets form on inland water.

Forces-of-Nature sports

Surfing, kite-buggying with small kites, kite-surfing with medium sized kites, windsurfing with 5.0-6.0m sails

Force Six - Strong breeze (22-27 knots)

Sea state:

Large waves begin to form. The white foam crests are more extensive everywhere. Probably some spray.

From land:

Large branches in motion. Whistling in telegraph wires. Umbrellas used with difficulty.

Forces-of-Nature sports

Kite-surfing with small kites, windsurfing with 5.0m sails and small boards.

Force Seven - Near gale (28-33 knots)

Sea state:

Sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind.

From land:

Whole trees in motion. Inconvenience felt when walking against the wind.

Forces-of-Nature sports

Windsurfing with 4.0-4.5m sails and small boards, kitesurfing for experts with small kites.

Force Eight - Gale (34-40 knots)

Sea state:

Moderately high waves of greater length. Edges of crests begin to break into spindrift. The foam is blown in well-marked streaks along the direction of the wind.

From land:

Breaks twigs off trees. Generally impedes progress.

Forces-of-Nature sports

Windsurfing with 3.0-4.0m sails.

Force Nine - Strong gale (41-47 knots)

Sea state:

High waves. Dense streaks of foam along the direction of the wind. Crests of waves begin to topple, tumble, and roll over. Spray may affect visibility.

From land:

Slight structural damage occurs (chimney pots and slates removed).

Forces-of-Nature sports

Windsurfing with 3.0-4.0m sails in 'survival' conditions.

Force Ten - Storm (48-55 knots)

Sea state:

Very high waves with long over-hanging crests. Foam in great patches is blown in dense white streaks along the direction of the wind. The surface takes on a white appearance. The tumbling of the sea becomes heavy and shock-like. Visibility affected.

From land:

Seldom experienced inland. Trees uprooted. Considerable structural damage occurs.

Forces-of-Nature sports

Find somewhere sheltered.

Force Eleven - Violent Storm (56-63 knots)

Sea state:

Sea covered in foam patches, with waves high enough to hide medium-sized vessels and with crests blown into froth, visibility affected.

From land:

Very rare on land, causing widespread damage.

Forces-of-Nature sports

Forget it.

Force Twelve - Hurricane (64+ knots)

Sea state:

Sea completely white, with driving spray, the air filled with foam and spray, visibility seriously impaired.

From land:

No description.

Forces-of-Nature sports

Yeah right...death on a stick mate!.