SEA DISTURBANCE SCALE

 

 

No.

Mean Wave Height

in Feet

Sea Description
0 - Calm
1

-

Ripples with the appearance of scales

formed but without foam crests

2

0.5

Small short wavelets.

Crests have a glassy appearance but do not break

3

2

Large wavelets. Crests begin to break with a little foam.

Perhaps some scattered white horses

4

3.5

Small waves becoming longer.

Fairly frequent white horses

5

6

Moderate pronunced long waves.

Many white horses with the chance of some spray

6

9.5

Large waves begin to form.

White foam crests are more extensive everywhere with the probability of spray.

7

13.5

Sea heaps up with white foam from breaking waves.

Spindrift begins to be seen.

8

18

Moderately high waves of greater length; edges of crests

break into spindrift. Foam blown into well-marked streaks

9

23

High waves with some dense streaks of foam

Crests begin to roll over. Spray may affect visibility

10

29

Very high waves with long overhanging crests.

Great patches of foam in dense white streaks.

Sea surface is white.Tumbling of sea becomes heavy.

Visibility affected

11

37

Exceptionally high waves.

Small and medium sized ships may be lost to view.

Sea completely covered with foam.

Edges of wave egess blown into froth. Visibility affected

12 45+

Sea completely white with driving spray.

Air filled with foam and spray.

Visibility very seriously affected.