What Is the Beaufort Scale?
The universal 0–12 scale for wind strength — knowing the answer to “how many Beaufort?” is what lets you plan at sea.
At sea how many Beaufort? has one answer, because Beaufort is the universal scale that grades wind strength from 0 to 12 according to the sea state and what is happening around it. Weather reports, VHF broadcasts and storm warnings all use this language. The good news: you do not need to memorise all 12 stages; for a boat owner, knowing three or four key thresholds is enough.
The table below gives each grade together with wind speed (knots), the look of the sea, and what you should do. The figures are for average wind; gusts can run one or two grades higher, and it is usually the gusts that strain lines and awnings.
Beaufort scale
Beaufort | Wind (kn) | Name | Sea state | For the boat owner |
|---|---|---|---|---|
0-1 | 0-3 | Calm / light air | Like a mirror, with a slight ripple | Relaxed — fine to run under power |
2-3 | 4-10 | Light breeze | Small wavelets, the odd patch of foam | Pleasant sailing weather, no issue |
4 | 11-16 | Moderate breeze | Small waves with frequent whitecaps | Typical afternoon meltemi range |
5 | 17-21 | Fresh breeze | Moderate waves, widespread white foam | Think about reefing; keep the plan disciplined |
6 | 22-27 | Strong breeze | Large waves, foam spreading | Time for a mooring check in the marina; comfort is over |
7 | 28-33 | Near gale | Sea builds, foam streaks appear | Question whether to go out; stay in the bay |
8-9 | 34-47 | Gale | High waves, blown spray | Storm-prep mode: lines, fenders, canopy |
10-12 | 48+ | Storm and above | Very high seas, poor visibility | Boat should be in a sheltered berth; no business being at sea |
Three thresholds to remember
5-6 Beaufort: your plan at sea needs to be disciplined; aim to be back before the afternoon breeze builds.
7 Beaufort: time for a marina mooring check and canopy check; most day-trip plans should be cancelled.
8 and above: storm preparation; in Göcek winter, these warnings often come with lodos, that is, south-westerlies.
One last practical tip: look at the expected gust rather than just the figure in the report. In funnelled bay entrances and on mountain downdrafts, local wind can run one or two grades above the general forecast.