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														BEAUFORT WIND SCALE
Bft	m/sec				km/h				Knots Wind				Wave  Height in m				W M O  Description	Effects observed on sea
0	0,0	-	0,2		0	-	1		0	-	1						Calm	Sea like mirror.
1	0,3	-	1,5		1	-	5		1	-	3		0,1				Light air	Ripples with appearance of scales; no foam crests.
2	1,6	-	3,3		6	-	11		4	-	6		0,2	-	0,5		Light breeze	Small wavelets; crests of glassy appearance, not  breaking.
3	3,4	-	5,4		12	-	19		7	-	10		0,5	-	1,0		Gentle breeze	Large wavelets; crests begin to break; scattered  whitecaps.
4	5,5	-	7,9		20	-	28		11	-	16		1,0	-	2,0		Moderate breeze	Small waves, becoming longer; numerous whitecaps.
5	8,0	-	10,7		29	-	38		17	-	21		2,0	-	3,0		Fresh breeze	Moderate waves, taking longer form; many white  caps; some spray.
6	10,8	-	13,8		39	-	49		22	-	27		3,0	-	4,0		Strong breeze	Larger waves forming whitecaps everywhere;  more spray.
7	13,9	-	17,1		50	-	61		28	-	33		4,0	-	5,5		Near Gale	Sea heaps up; white foam from breaking waves  begin to be blown in streaks.
8	17,2	-	20,7		62	-	74		34	-	40		5,5	-	7,5		Gale	Moderately high waves of greater length; edges of  crests begin to break into spindrift; foam is blown in  well-marked streaks.
9	20,8	-	24,4		75	-	88		41	-	47		7,0	-	10,0		Strong gale	High waves; sea begins to roll; dense streaks of  foam; spray may reduce visibility.
10	24,5	-	28,4		89	-	102		48	-	55		9,0	-	12,5		Storm	Very high waves with overhanging crests; sea takes  white appearance as foam is blown in very dense  streaks; rolling is heavy and visibility reduced.
11	28,4	-	32,6		103	-	117		56	-	63		11,5	-	16,0		Violent storm	Exceptionally high waves; sea covered with foam  patches; visibility still more reduced.
12	32,7	-			118	-	133		64	-	71		14,0		+		Hurricane	Air filled with foam; sea completely white with driving  spray; visibility greatly reduced.