Question 721Navigation General

The correct answer is C) 11.0 knots. To calculate the speed of the true wind, we need to use the vector addition of the vessel's speed and the apparent wind speed. Since the apparent wind is from 40° off the starboard bow, we can use the trigonometric formula to find the true wind speed: True Wind Speed = sqrt((Vessel Speed)^2 + (Apparent Wind Speed)^2 - 2*(Vessel Speed)*(Apparent Wind Speed)*cos(Relative Angle)). Plugging in the given values, we get: True Wind Speed = sqrt((17)^2 + (15)^2 - 2*(17)*(15)*cos(40)) = 11.0 knots. The other answer choices are incorrect because they do not match the result of the trigonometric calculation.