Your ship is proceeding on course 320°T at a speed of 25 knots. The apparent wind is from 30° off the starboard bow, speed 32 knots. What is the relative direction, true direction and speed of the true wind?

Correct Answer: Option B — Relative 80°, true 040°T, 16.2 knots

Using relative vector addition triangles for apparent and ship's motion as outlined in Bowditch, subtracting ship's vector from apparent wind vector yields a relative wind of 80°, true direction 040°T, and 16.2 knots.