Your vessel is on a course of 223°T at 17...

Question 1 of 2707066636ee928f7522a1c51a5b6

Your vessel is on a course of 223°T at 17 knots. At 1323 a lighthouse bears 318° relative. At 1341 the same lighthouse bears 287° relative. What is your distance off the lighthouse at 1341?

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Question 1 of 27070

Your vessel is on a course of 223°T at 17 knots. At 1323 a lighthouse bears 318° relative. At 1341 the same lighthouse bears 287° relative. What is your distance off the lighthouse at 1341?

🔍 Key Concepts

• Relative bearings and how they change as you pass an object abeam • Speed–time–distance relationship: $\text{Distance} = \text{Speed} \times \text{Time}$ • Using a right triangle formed by two relative bearings and the ship’s track to find distance off (perpendicular distance)

💭 Think About

• Convert the time between the two bearings into hours and find how far the vessel traveled between 1323 and 1341 at 17 knots. What is that distance? • Sketch your ship’s track as a straight line and plot the lighthouse at the vertex of two lines representing the two relative bearings. Where is the ship at 1341 relative to the lighthouse? • Once you know the run between the two bearings and the included angle between them, how can basic trigonometry give you the perpendicular distance from your track to the lighthouse at the second bearing?

✅ Before You Answer

• Be sure you are using relative bearings, not true bearings, when constructing your triangle. • Confirm your time difference (in minutes) and convert correctly to hours before multiplying by 17 knots. • Double-check which side of the triangle represents the distance off at 1341 (perpendicular from the lighthouse to your track), not the total run or slant range.