| Force | Km/h | Mph | Knots | Wind | Probable sea   state | 
                
                  | 0 | less than 1 | less than 1 | less than 1 | Still | Like a mirror | 
                
                  | 1 | 1-5 | 1-3 | 1-3 | Very light | Ripples with appearance of scales. No crests. | 
                
                  | 2 | 6-11 | 4-7 | 4-6 | Light breeze | Small wavelets. Glassy crests that don't break. | 
                
                  | 3 | 12-19 | 8-12 | 7-10 | Gentle breeze | Crests begin to break | 
                
                  | 4 | 20-29 | 13-18 | 11-16 | Moderate breeze | Waves becoming larger, frequent white horses | 
                
                  | 5 | 30-39 | 19-24 | 17-21 | Fresh breeze | Moderate waves, many white horses, some spray | 
                
                  | 6 | 40-50 | 25-31 | 22-27 | Strong breeze | Large waves, extensive white horses | 
                
                  | 7 | 51-61 | 32-38 | 28-33 | Near gale | Sea heaps up, waves breaking, white foam blown in   streaks | 
                
                  | 8 | 62-74 | 39-46 | 34-40 | Gale | Moderate high waves, crests break into spindrift, white   foam | 
                
                  | 9 | 75-87 | 47-54 | 41-47 | Strong gale | High waves, crests topple spray affects visibility | 
                
                  | 10 | 88-101 | 55-63 | 48-55 | Storm | Very high breaking waves, dense foam streaks |