The Beaufort Scale for Surfers

Beaufort number	Wind speed				Description	Wave height		Sea conditions	Sea state photo
	km/h	mph	kts	m/s		m	ft
0	<1	<1	<1	<0.3	Calm	0	0	Sea like a mirror.
1	1-5	1-3	1-2	0.3-1.5	Light air	0.1	0.33	Ripples without crests.
2	6-11	3-7	3-6	1.5-3.3	Light breeze	0.2	0.66	Small wavelets. Crests of glassy appearance, not breaking
3	12-19	8-12	7-10	3.3-5.5	Gentle breeze	0.6	2	Large wavelets. Crests begin to appear; scattered whitecaps
4	20-28	13-17	11-15	5.5-8.0	Moderate breeze	1	3.3	Small waves becoming longer. Fairly frequent with ‘white horses’
5	29-38	18-24	16-20	8.0-10.8	Fresh breeze	2	6.6	Moderate waves with more pronounced long form. Some foam and spray.
6	39-49	25-30	21-26	10.8-13.9	Strong breeze	3	9.9	Larger waves begin to form. Spray is present. White foam and crestsare everywhere.
7	50-61	31-38	27-33	13.9-17.2	High wind, Moderate Gale, Near Gale	4	13.1	Sea heaps up and foam begins to streak.
8	62-74	39-46	34-40	17.2-20.7	Fresh Gale	5.5	18	Moderately high waves with breaking crests forming spindrift. Streaks of foam along wind direction.
9	75-88	47-54	41-47	20.7-24.5	Strong Gale	7	23	High waves (6-7 m) with dense foam. Wave crests start to roll over. Considerable spray.
10	89-102	55-63	48-55	24.5-28.4	Whole Gale/Storm	9	29.5	Very high waves. Large patches of foam from wave crests give the sea a white appearance. Considerable tumbling of waves with heavy impact. Large amounts of airborne spray reduce visibility.
11	103-117	64-72	56-63	28.4-32.6	Violent storm	11.5	37.7	Exceptionally high waves. Very large patches of foam, driven before the wind, cover much of the sea surface. Very large amounts of airborne spray severely reduce visibility.
12	>118	>73	>64	>32.6	Hurricane-force	>14	>46	Huge waves. Sea is completely white with foam and spray. Air is filled with driving spray, greatly reducing visibility.