Question 1143Navigation General

The correct answer is C) apparent wind direction. A wind vane on a moving vessel measures the apparent wind direction, which is the direction the wind appears to be coming from relative to the vessel's motion. This is different from the true wind direction, which is the direction the wind is actually blowing from. The apparent wind direction is affected by the vessel's speed and heading, while the true wind direction is not. The other options are incorrect because dead reckoning wind direction refers to estimating the wind direction based on the vessel's course and speed, and estimated wind direction is a general term that does not specifically refer to the measurement from a wind vane on a moving vessel.