The Beaufort Wind Force scale (pronounced bow-fort) is an empirical measure for describing wind speed based mainly on observed conditions.
   In the early 19th Century, naval officers made regular weather observations, but there was no standard scale and so they could be very subjective - one man’s "stiff breeze" might be another’s "soft breeze". Sir Francis Beaufort, an Irish-born British admiral and hydrographer, created the scale in 1805. His scale set forth 13 increasingly powerful wind forces based on descriptions of how they affected a ship's sails.  Each force was given a name, ranging from Force 0 which is calm to Force 12, which is a hurricane.  The Beaufort Scale was made a standard for ship’s log entries on Royal Navy vessels in the late 1830s.
    In the 1850s, the newly invented anemometer provided actual wind speeds which were incorporated into the scale.  The growth of steam power resulted in the original scale being changed from descriptions of how the sails reacted to how the sea reacted to various wind forces. It was later expanded to include land conditions.
   The various terms established by Admiral Beaufort are widely used today. This poster lists each of the forces by name and number. Wind speed is given in statue miles, nautical miles and kilometers per hour.  It shows the conditions on both land and sea at various wind forces. Under each one, a brief description describes the conditions. 
   The dramatic presentation shows increasingly powerful winds and waves destroy a beach cottage, severely erode the shoreline and actually flip the sailboat upside down. Due to it maintaining watertight integrity, the weight of the ballast rights it, so the boat survives.
   This poster was prepared with the assistance of the U.S. National Weather Service and the U.S. Coast Guard Office of Boating Safety.  Admiral Beaufort's original scale included recommended sail settings. We have followed his example. The famous Annapolis Sailing School provided information on sail setting and boat handling.
   Knowing the information presented on this poster permits anyone to accurately determine the wind speed, based solely on personal observations, just like the master mariners of yesteryear.