Your vessel is underway on a course of 115°T at 18 knots. At 1850 a lighthouse bears 137.5°T. At 1920, the same lighthouse bears 160°T. What time will the lighthouse pass abeam to starboard?

Correct Answer: Option A — 1941

Applying Bowditch relative motion and running fix principles, calculate the time interval and change in bearing to determine when the lighthouse will bear exactly abeam (90 degrees relative to the heading).