|
|
| Force |
Wind Speed (Kts) |
Description |
Effects at Sea |
Effects Near Land |
| 0 |
under 1 |
Calm |
Sea like a mirror |
Calm |
| 1 |
1-3 |
Light Air |
Ripples with appearance of scales; no foam crests |
Small sailboat just has steerage way |
| 2 |
4-6 |
Light Breeze |
Small wavelets; crests of glassy appearance, not breaking |
Wind fills the sails of small boats which then travel at about 1-2 knots |
| 3 |
7-10 |
Gentle Breeze |
Large wavelets; crests begin to break, scattered whitecaps |
Sailboats begin to heel and travel at about 3-4 knots |
| 4 |
11-16 |
Moderate Breeze |
Small waves 0.5-1.25 meters high, becoming longer; numberous whitecaps |
Good working breeze, sailboats carry all sail with good heel |
| 5 |
17-21 |
Fresh Breeze |
Moderate waves of 1.25-2.5 meters taking longer form; many whitecaps; some spray |
Sailboats shorten sail |
| 6 |
22-27 |
Strong Breeze |
Larger waves 2.5-4 meters forming; whitecaps everywhere; more spray |
Sailboats have double reefed mainsails |
| 7 |
28-33 |
Near Gale |
Sea heaps up, waves 4-6 meters; white foam from breaking waves begins to be blown in streaks |
Boats remain in harbor; those at sea heave-to |
| 8 |
34-40 |
Gale |
Moderately high (4-6 meter) waves of greater lenght; edges of crests begin to break into spindrift; foam is blown in well-marked streaks |
All boats make for harbor, if near |
| 9 |
41-47 |
Strong Gale |
High waves (6 meters); sea begins to roll; dense streaks of foam; spray may reduce visibility |
|
| 10 |
48-55 |
Storm |
Very high waves (6-9 meters) with overhanging crests; sea takes a white appearance as foam is blown in very dense streaks; rolling is heavy and visibility is reduced |
|
| 11 |
56-63 |
Violent Storm |
Exceptionally high (9-14 meters) waves; sea covered with white foam patches; visibility still more reduced |
|
| 12 |
64-over |
Hurricane |
Air filled with foam; waves over 14 meters; sea completely white with driving spray; visibility greatly reduced |
|
