You are steering a course of 316°T, and a light bears 34° on the port bow at 2053. At 2126 the same light bears 68° on the port bow, and you have run 5 miles since the first bearing. What is the ETA when the lighthouse is abeam?

Question

You are steering a course of 316°T, and a light bears 34° on the port bow at 2053. At 2126 the same light bears 68° on the port bow, and you have run 5 miles since the first  bearing. What is the ETA when the lighthouse is abeam?

Accepted Answer

Option B: 2139. Applying the running fix principles and Bowditch navigation methods, the time interval between bearings yields the run distance. Speed made good determines the time required to cover the remaining distance to the beam bearing, establishing the precise estimated time of arrival at 2139.