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 which time and distance off will your vessel be when abeam of this light?

Question

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 which time and distance off will your vessel be when abeam of this light?

Accepted Answer

Option A: 2021, 3.9 miles. Using the two-bearing method and piloting principles, the time elapsed between 1937 and 2003 is 26 minutes. Calculations for a course of 129 degrees and bearings of 151.5 and 174 degrees determine abeam at 2021 with a distance off of 3.9 miles.