Question 1107Navigation General

The correct answer is D) apparent wind speed only. An anemometer on a moving vessel measures the apparent wind speed, which is the speed of the wind as experienced by a person on the moving vessel. Apparent wind is the combination of the true wind and the vessel's motion. The anemometer cannot directly measure the true wind speed and direction, which are the actual wind conditions independent of the vessel's movement. The other options are incorrect because an anemometer on a moving vessel does not measure true wind speed and direction (A), nor can it measure true wind direction alone (B or C).