0

Calm

Sea like a mirror.

0.1

0.1

1

2

1

Light Air

Ripples with the appearance of scales formed.

0.2

0.3

2

5

3

Light Breeze

Small wavelets, more pronounced. Crests glassy appearance, do not break.

0.6

1.0

3

9

4

Gentle Breeze

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

1.0

1.5

4

14

7

Moderate Breeze

Small waves, becoming longer; fairly frequent white horses.

2.0

2.5

5

19

10

Fresh Breeze

Moderate waves, more pronounced long foam; many white horses
(Some spray).

3.0

4.0

6

25

13

Strong Breeze

Large waves, white foam more extensive everywhere (Spray).

4.0

5.5

7

31

15

Near Gale

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

5.5

7.5

8

37

19

Gale

Moderately high waves of greater length; edges of crests break into
spindrift. Foam blown in well marked streaks.

7.5

10.5

9

44

23

Strong Gale

High waves. Dense streaks of foam. Sea begins to roll. Spray may
affect visibility.

9.0

12.5

10

54

27

Storm

Very high waves with long overhanging crests. Foam in great patches
blown in dense white streaks. Surface of sea takes white appearance.
Rolling sea becomes heavy. Visibility affected.

11.5

16.0

11

60

31

Violent Storm

Exceptionally high waves (small and medium sized ships lost to view
behind waves). Sea is completely covered with long white patches of
foam. Edges of wave crests blown into froth. Visibility affected.

14.0

---

12

64

33

Hurricane

Air filled with foam and spray. Sea completely white with driving spray;
visibility seriously affected.

0

Glassy Calm

0 mtr

1

Calm

0 to 0.1 mtr

2

Smooth

0.1 to ½ mtr

3

Slight

½ to 1¼ mtrs

4

Moderate

1¼ to 2½ mtrs

5

Rough

2½ to 4 mtrs

6

Very Rough

4 to 6 mtrs

7

High

6 to 8 mtrs

8

Very High

8+ mtrs