To Previous PageBeaufort Wind Scale

 Force 

Knots*

Wind State

 Sea Conditions

0

1 or less

Calm

Like a mirrorLike a mirror

1

1-3

Light Aire

Ripples like scales

2

4-6

Light Breeze

Small wavelets, glassy crests, not breaking

3

7-10

Gentle Breeze

Large wavelets, crests beginning to break, glassy foam

4

11-16

Moderate Breeze

Small waves, becoming longer, fairly frequent white horses Slight

5

17-21

Fresh Breeze

Moderate waves, more pronounced long form, many white horses, possibly some spray

6

22-27

Strong Breeze

Large waves begin to form, white crests more extensive everywhere. Possibly some spray

7

28-33

Near Gale

Sea heaps up with white foam from breaking waves

8

34-40

Gale

Moderately high waves of greater length, much foam

9

41-47

Strong Gale

High waves, crests of waves start to topple and roll over, dense streaks of foam along the direction of wind

10

48-55

Storm

Very high waves, overhanging crests, resulting foam is blown in dense white patches with the wind, sea surface takes on a whiter look.

11

56-65

Severe Storm

Exceptionally high waves, sea covered with long white patches of foam blown in direction of wind. All wave crests are blown into froth.

12

66+

Hurricane

Air is filled with spray and foam, sea is completely white with driving spray. Visibility is seriously affected.