Your vessel is on a course of 255°T, at 14 knots. At 2116 a lighthouse is sighted dead ahead at a distance of 11 miles. You change course at this time to pass the lighthouse 3 miles abeam to port. What will be your ETA at this position off the lighthouse?

Correct Answer: Option B — 2201

Using the relative motion triangle, the lighthouse is 11 miles ahead. Changing course to pass 3 miles abeam requires a course change. The distance to the beam position is calculated via trigonometry. At 14 knots, the run time is 45 minutes from 2116, resulting in an ETA of 2201.