Knot (Speed)

A knot is the unit of speed equal to one nautical mile per hour, the standard for vessel speed, wind speed, and current speed in marine and aviation reporting. One nautical mile is 1,852 meters, so one knot is 0.5144 meters per second or 1.852 kilometers per hour. The name comes from the old chip-log practice of counting knots in a line paid out over a timed interval. Marine observation logs, weather forecasts, scatterometer wind products, and ship speed-over-ground all report in knots, which keeps speed tied directly to nautical miles of distance on a chart.