Beaufort Scale
| Force | Description | Wind speed |
| 0 | Calm | < 1 knot |
| 1 | Light air | 1-2 knots |
| 2 | Light breeze | 3-6 knots |
| 3 | Gentle breeze | 7-10 knots |
| 4 | Moderate breeze | 11-15 knots |
| 5 | Fresh breeze | 16-20 knots |
| 6 | Strong breeze | 21-26 knots |
| 7 | High wind, moderate gale, near gale | 27-33 knots |
| 8 | Gale, fresh gale | 34-40 knots |
| 9 | Strong gale | 41-47 knots |
| 10 | Storm, whole gale | 48-55 knots |
| 11 | Violent storm | 56-63 knots |
| 12 | Hurricane | > 64 knots |
