BEAUFORT WIND SCALE AND SEA HEIGHT RELATIONSHIPS
| BEAUFORT LEVEL |
WIND SPEED |
SEA STATE AND WAVE HEIGHT LEVELS |
| FORCE 0 |
LESS THAN 1 KNOT |
SEA LIKE A MIRROR |
| FORCE 1 |
1 - 3 KNOTS |
WAVE HEIGHT .1 M(.25 FT.); RIPPLES WITH APPEARANCE OF SCALES, NO FOAM CRESTS. |
| FORCE 2 |
4 - 6 KNOTS |
WAVE HEIGHT .2 - .3 (.5 - 1 FT.); SMALL WAVELETS, CRESTS OF GLASSY APPEARANCE, NOT BREAKING. |
| FORCE 3 |
7 - 10 KNOTS |
WAVE HEIGHT .6 - 1 M (2 - 3 FT.); LARGE WAVELETS, CRESTS BEGIN TO BREAK, SCATTERED WHITECAPS. |
| FORCE 4 |
11 - 16 KNOTS |
WAVE HEIGHT 1 - 1.5 M (3.5 - 5 FT.); SMALL WAVES BECOMING LONGER, NUMEROUS WHITECAPS. |
| FORCE 5 |
17 - 21 KNOTS |
WAVE HEIGHT 2 - 2.5 M (6 - 8 FT.); MODERATE WAVES, TAKING LONGER FORM, MANY WHITECAPS, SOME SPRAY. |
| FORCE 6 |
22 - 27 KNOTS |
WAVE HEIGHT 3 - 4 M (9.5 - 13 FT.); LARGER WAVES FORMING, WHITECAPS EVERYWHERE, MORE SPRAY. |
| FORCE 7 |
28 - 33 KNOTS |
WAVE HEIGHT 4 - 5.5 M (13.5 - 19 FT.); SEA HEAPS UP, WHITE FORM FROM BREAKING WAVES BEGINS TO BE BLOWN IN STREAKS ALONG DIRECTION OF WIND. |
| FORCE 8 |
34 - 40 KNOTS |
WAVE HEIGHT 5.5 - 7.5 M (18 - 25 FT.); MODERATELY HIGH WAVES OF GREATER LENGTH, EDGES OF CRESTS BEGIN TO BREAK INTO SPINDRIFT, FOAM IS BLOWN IN WELL MARKED STREAKS. |
| FORCE 9 |
41 - 47 KNOTS |
WAVE HEIGHT 7 - 10 M (23 - 32 FT.); HIGH WAVES, SEA BEGINS TO ROLL, DENSE STREAKS OF FOAM ALONG WIND DIRECTION, SPRAY MAY REDUCE VISIBILITY. |
| FORCE 10 |
48 - 55 KNOTS |
WAVE HEIGHT 9 - 12.5 M (29 - 41 FT.); VERY HIGH WAVES WITH OVERHANGING CRESTS, SEA TAKES WHITE APPEARANCE AS FOAM IS BLOWN IN VERY DENSE STREAKS, ROLLING IS HEAVY AND SHOCKLIKE, VISIBILITY IS REDUCED. |
| FORCE 11 |
56 - 63 KNOTS |
WAVE HEIGHT 11.5 - 16 M (37 - 52 FT.); EXCEPTIONALLY HIGH WAVES, SEA COVERED WITH WHITE FOAM PATCHES, VISIBILITY IS STILL MORE REDUCED. |