The Beaufort Scale
SPÉÉP
O Knots O mph O km/h
Sea like a mirror
Smoke rises vertically
UANP
"Calm''
SPÉÉP
1-3 Knots 1-3 mph 1-6 km/h
LANP
Ripples with the appearance of scales are formed/ but without foam crests
direction of wind shown by smoke but not by wind vanes
FORCÉ
SPÉÉP
11-16