You depart LAT 40°42.0'N, LONG 74°01.0'W, and steam 3365.6 miles on course 118°T. What is the longitude of your arrival by Mercator sailing?

Correct Answer: Option B — 17°41.0'W

Mercator sailing utilizes the difference in meridional parts (DMP) to calculate longitude. By applying the formula tan(Course) = Departure / DLat and relating departure to DLong via the mean latitude or DMP, the resulting change in longitude confirms the arrival at 17°41.0'W, consistent with Bowditch principles.