| Beaufort Number (Force) | Wind Speed (knots) | Wave Height (Feet) | Wind Description | As Observed At Sea |
|---|---|---|---|---|
| 0 | Under 1 | Calm | Sea surface as a mirror. | |
| 1 | 1-3 | 0.3 | Light Air | Ripples appearing like scales, no foam crests. |
| 2 | 4-6 | 0.5-1 | Light Breeze | Small wavelets, crests glassy appearing, not breaking. |
| 3 | 7-10 | 2-3 | Gentle Breeze | Large wavelets, crests begin to break, scattered whitecaps. |
| 4 | 11-16 | 3 1/2-5 | Moderate Breeze | Small waves becoming longer, numerous whitecaps. |
| 5 | 17-21 | 6-8 | Fresh Breeze | Moderate waves taking longer form, many whitecaps, some spray. |
| 6 | 22-27 | 9 1/2-13 | Strong Breeze | Larger waves forming, whitecaps everywhere, more spray. |
| 7 | 28-33 | 13 1/2-18 | Near Gale | Sea heaps up, white foam from breaking waves begins to be blown in streaks. |
| 8 | 34-40 | 19-25 | Gale | Moderately high waves with greater length, edges of crests begin to break into spindrift, foam is blown in well marked streaks. |
| 9 | 41-47 | 23-33 | Strong Gale | High waves as sea begins to roll, dense streaks of foam, spray begins to reduce visibility. |
| 10 | 48-55 | 29-41 | Storm | Very high waves with overhanging crests. Sea takes on white appearance as foam is blown in very dense streaks, rolling is heavy and visibility is reduced. |
| 11 | 56-63 | 37-52 | Violent Storm | Exceptionally high waves. Sea covered with white foam patches, visibility more reduced. |
| 12 | 64-71 | 50 and over | Hurricane | Exceptonally high waves, air filled with foam, sea completely white with driving spray, visibility greatly reduced, barely navigable under storm canvas or bare poles running on proper tack trailing drogue toward navigable semi-circle away from path of storm. |
| 13 - 17 | 72-118 and over | 50 and over | Hurricane | Exceedingly high waves, air filled with foam, sea obscured by driven spray, visibility nearly impossible, for all purposes not navigable, hove to on parachute sea anchor. |
The Voyages of the Atha Windwalker
20040319
