A vessel at LAT 28°00'N, LONG 116°00'W is to proceed to LAT 34°00'N, LONG 123°40'W. What is the course and distance by mid-latitude sailing?

Correct Answer: Option D — 312°T, 533 miles

Mid-latitude sailing uses the mean latitude between two points to approximate the departure. Calculating the difference in latitude (360') and departure (diff long * cos mid-lat), the course is found via tan(Course) = Departure / DLat. The resulting course is 312°T with a distance of 533 miles.