Beaufort
The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land; spindrift - spray, particularly spray blown from cresting waves - is part of the definition for no. 8 on the scale, a gale or fresh gale, which is defined for wind at sea as: "Moderately high waves of greater length; edges of crests break into spindrift; foam is blown in well-marked streaks along the direction of the wind". The Fujita Scale measures tornado intensity; the Saffir-Simpson gives a rating relative to hurricanes; "Aeolian", although it relates to wind, is not a scale which uses spindrift to define it.
