Apparent wind in knots and degrees. Note that a number of additional factors come into play when converting the measurements from the masthead anemometer into the true wind if a high degree of accuracy is required, including the following: In the presence of a current, the true wind is considered to be that measured on the craft drifting with the water over the bottom, and wind with respect to the sea bed as the "ground" or "geographical wind". The apparent wind on board (a boat) is often quoted as a speed measured by a masthead transducer containing an anemometer and wind vane
Wind transducer Wind transducer A wind transducer is a device used by sailors to receive a real-time measurement of wind speed and direction. A wind transducer is usually mounted on the masthead of a sailing boat and is occasionally used by power boats too. The wind speed and direction measurements are more critical to sailing boats than to power boats. Sailors rely on the wind speed and direction to help with navigation and pilotage. These devices can be calibrated to measure the true wind speed and the apparent wind speed (speed that a sailor would 'feel'). Sailing boats can sail at a