The Beaufort Scale
- The Beaufort scale divides wind into 13 categories or forces based on speed, description and affect on the water. Calm wind has a force of zero on the Beaufort scale, moves about 1 mile per hour and produces no visible effects on the water. A hurricane has a force of 12 on the Beaufort scale, speeds in excess of 74 miles per hour and fills the air with sea spray, seriously degrading visibility.
- The Beaufort scale divides gale force winds into near gales and strong gales. A near gale has a force of eight on the Beaufort scale and a speed between 40 and 46 miles per hour. A strong gale has a force of nine on the Beaufort scale and a speed between 47 and 54 miles per hour.
- High waves with crests that break into spindrift indicate a near gale force wind. A strong gale is indicated by large waves that crest and roll over with thick streaks of foam that move in the direction of the wind.