This table can help converting windspeeds:
| Beaufort | Knots | Mph | Appearance on water |
| 0 | under 1 | under 1 | Water like a mirror. |
| 1 | 1-3 knots | 1-3 mph | Dull areas on the water (not glassy). |
| 2 | 4-6 knots | 4-6 mph | Small wavelets. |
| 3 | 7-10 knots | 8-12 mph | Small wavelets, maybe a couple of whitecaps. |
| 4 | 11-16 knots | 13-18 mph | Small waves, whitecaps. |
| 5 | 17-21 knots | 19-24 mph | Medium waves, whitecaps. |
| 6 | 22-27 knots | 25-31 mph | Large waves, whitecaps everywhere, some spray off the water. |
| 7 | 28-33 knots | 32-38 mph | Large waves, whitecaps everywhere, spray off the water. |
| 8 | 34-40 knots | 39-46 mph | Big swells of greater length, streaks of white spray from the water. |
| 9 | 41-47 knots | 47-54 mph | Huge swells, spray everywhere, walking is difficult. |
| 10 | 48-55 knots | 55-63 mph | Huge waves, difficult to see, spray everywhere. |