While on a course of 279°T, a light bears 12° on the starboard bow at a distance of 9.3 miles. What course should you steer to pass 4 miles abeam of the light leaving it to starboard?

Question

While on a course of 279&deg;T, a light bears 12&deg; on the starboard bow at a distance of 9.3 miles. What course should you steer to pass 4 miles abeam of the light leaving it to starboard?

Accepted Answer

Option C: 265&deg;T. Current distance off is 9.3 * sin(12 degrees) = 1.93 miles. To increase to 4 miles, the required course change is arcsin((4 - 1.93) / 9.3) = 12.8 degrees. Subtracting this shift away from the light from the original course of 279 degrees T results in a new course of 265 degrees T.

While on a course of 279&deg;T, a light bears 12&deg; on the starboard bow at a distance of 9.3 miles. What course should you steer to pass 4 miles abeam of the light leaving it to starboard?

While on a course of 279°T, a light bears 12° on the starboard bow at a distance of 9.3 miles. What course should you steer to pass 4 miles abeam of the light leaving it to starboard?