Your vessel is on a course of 129° T at 13...

Question 1 of 2707066636eea28f7522a1c51b794

Your vessel is on a course of 129° T at 13 knots. At 1937 a light bears 151.5° T. At 2003 the light bears 174° T. At what time and distance off will your vessel be when abeam of this light?

Back

Question 1 of 27070

Your vessel is on a course of 129° T at 13 knots. At 1937 a light bears 151.5° T. At 2003 the light bears 174° T. At what time and distance off will your vessel be when abeam of this light?

🔍 Key Concepts

• Relative motion of bearings as you pass a light abeam • Using change in bearing over time to find time to abeam on a constant course and speed • Converting time difference and speed into distance run

💭 Think About

• Sketch the situation with your course line and the two observed bearings. Where will the abeam bearing (90° from your course) fall on that sketch? • How much does the bearing change between the first and second observation, and how much more does it need to change to become abeam? • Once you know the fraction of the total bearing change that remains until abeam, how can you apply that same fraction to the known time interval between the two bearings?

✅ Before You Answer

• Confirm what the abeam bearing should be in true degrees for a ship on course 129° T (i.e., 90° on the appropriate side). • Check that you are assuming constant course and speed between 1937 and the time abeam. • After finding the time from the second bearing to abeam, convert total time from the first bearing to abeam into hours, then multiply by 13 knots to get distance in nautical miles.