You are steering a course of 240°T, and a lighthouse bears 025° on the starboard bow at 2116. At 2144 the same lighthouse bears 050° on the starboard bow, and you have run 6 miles since the first bearing. What is the ETA when the lighthouse is abeam?

Question

You are steering a course of 240&deg;T, and a lighthouse bears 025&deg; on the starboard bow at 2116. At 2144 the same lighthouse bears 050&deg; on the starboard bow, and you have run 6 miles since the first bearing. What is the ETA when the lighthouse is abeam?

Accepted Answer

Option B: 2202. The run between bearings is 28 minutes for 6 miles. The light is abeam when the bearing is 90 degrees. Using the time-distance-speed relationship, the remaining distance to the beam position is calculated via trigonometry. Adding the time required to cover that distance to the 2144 timestamp results in 2202.

You are steering a course of 240&deg;T, and a lighthouse bears 025&deg; on the starboard bow at 2116. At 2144 the same lighthouse bears 050&deg; on the starboard bow, and you have run 6 miles since the first bearing. What is the ETA when the lighthouse is abeam?

You are steering a course of 240°T, and a lighthouse bears 025° on the starboard bow at 2116. At 2144 the same lighthouse bears 050° on the starboard bow, and you have run 6 miles since the first bearing. What is the ETA when the lighthouse is abeam?