While on a course of 321°T, a light bears 7° on the starboard bow at a distance of 9.7 miles. What course should you steer to pass 3.5 miles abeam of the light leaving it to starboard?

Question

While on a course of 321&deg;T, a light bears 7&deg; on the starboard bow at a distance of 9.7 miles. What course should you steer to pass 3.5 miles abeam of the light leaving it to starboard?

Accepted Answer

Option B: 307&deg;T. Current distance off is 9.7 * sin(7 degrees) = 1.18 miles. To increase to 3.5 miles, the required course change is arcsin((3.5 - 1.18) / 9.7) = 13.8 degrees. Subtracting this shift away from the light from the original course of 321 degrees T results in a new course of 307 degrees T.

While on a course of 321&deg;T, a light bears 7&deg; on the starboard bow at a distance of 9.7 miles. What course should you steer to pass 3.5 miles abeam of the light leaving it to starboard?

While on a course of 321°T, a light bears 7° on the starboard bow at a distance of 9.7 miles. What course should you steer to pass 3.5 miles abeam of the light leaving it to starboard?