🔍 Key Concepts

• Relative (apparent) vs. true wind vectors – how the vessel’s motion changes what you feel on deck • Ship’s course and speed as a vector (180°T at 22 knots) and apparent wind as another vector (70° off the port bow at 20 knots) • Using vector addition/subtraction (head-to-tail triangle or right-angle components) to find the true wind direction and speed

💭 Think About

• Sketch the ship’s course as a vector pointing due south (180°T) and then sketch the apparent wind 70° off the port bow; think carefully about which quadrant that apparent wind lies in, relative to true north • Remember that apparent wind is the result of true wind and ship’s motion combined; decide whether you should add or subtract the ship’s velocity vector to recover the true wind • Break the vectors into north–south and east–west components using sine and cosine, then recombine to get the magnitude (speed) and angle (direction) of the true wind

✅ Before You Answer

• Be clear which way is port bow when you’re headed 180°T, and convert “70° off the bow” into a true bearing before you do any trig • Check that your component signs (north/south, east/west) are consistent with the sketch of the situation • After you compute the true wind, confirm that its direction and speed are reasonable: does the resulting true wind, combined with ship’s motion, produce an apparent wind from 70° off the port bow at 20 knots?