A ship is on course 195° at a speed of 15...

Question 1 / 27070

Question 1 of 2707066636ee928f7522a1c51a092

A ship is on course 195° at a speed of 15 knots. The apparent wind is from 40° on the port bow, speed 30 knots. What are the direction and speed of the true wind?

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Question 1 of 27070

A ship is on course 195° at a speed of 15 knots. The apparent wind is from 40° on the port bow, speed 30 knots. What are the direction and speed of the true wind?

🔍 Key Concepts

• Relative (apparent) wind vs. true wind and how the ship’s motion affects what you feel on deck • Using vector addition/subtraction between ship’s velocity and wind velocity • Converting a relative bearing like “40° on the port bow” into a true direction (true bearing) from north

💭 Think About

• Sketch the ship’s heading (195°T) and then show where “40° on the port bow” lies relative to that heading. What true direction does that correspond to? • Think of apparent wind as the combination of true wind and the ship’s own motion. Are you adding the ship’s velocity to the true wind, or subtracting it? Draw a vector diagram to decide. • Once you have your wind vectors drawn to scale (15 knots for the ship, 30 knots for apparent wind), which triangle law (head‑to‑tail) helps you find the true wind’s direction and magnitude?

✅ Before You Answer

• Be sure you’ve turned “40° on the port bow” into the correct side (port vs starboard) and the correct angle relative to the ship’s heading of 195°T. • Confirm that your final true wind direction is expressed as a bearing from 000°–359°T, not as a relative angle off the bow. • After constructing your vector triangle, double‑check that the true wind speed is reasonable: it should not be less than the difference between 30 knots and 15 knots, and not more than their sum.