Your vessel is on a course of 144°T at 20 knots. At 0022 a light bears 117.5°T, and at 0035 the light bears 099°T. At what time and at what distance off will your vessel be when abeam of the light?

Correct Answer: Option A — 0048, 4.3 miles

Calculate the distance off using the relative bearing change method. With a 13-minute interval at 20 knots, the distance run is 4.33 miles. Using the formula for distance off at the second bearing, the vessel will be 4.3 miles off the light at 0048.