A vessel at LAT 38°03.0'S, LONG 49°38.0'W, heads for a destination at LAT 41°26.0'S, LONG 38°32.0'W. Determine the true course by Mercator sailing.

Correct Answer: Option D — 111.5°T

Using Mercator sailing formulas, calculate the difference in latitude and difference in longitude. Determine the meridional parts for both latitudes. The formula tan(Course) = DLo / Meridional Parts Difference provides the true course. Applying these values results in a true course of 111.5°T for the specified coordinates.