You are steaming on a course of 084°T at a speed of 13 knots. At 1919 a lighthouse bears 106.5°T. At 1957 the same lighthouse bears 129°T. What will be your distance off the lighthouse when abeam?

Correct Answer: Option A — 5.7 miles

Applying standard piloting calculations for distance off when abeam using two bearings and run time at 13 knots along a 084-degree course yields a distance off of 5.7 nautical miles.