A unit indicating wind intensity, based on a scale named after Admiral Sir Francis Beaufort. A low Beaufort number indicates little or no wind, and a high number means higher wind. Beaufort numbers are NOT directly tied to given speeds. Boomerangs can be thrown in the 0-5 Beaufort range, but it's not much fun beyond about 3 or 4 (very approximately 15 km/hr). Beaufort number 12 (a hurricane) means trees are uprooted, and your limp, lifeless body flies farther than your boomerang (which does not return to you).