A vessel steams 666 miles on course 135°T from LAT 40°24.0'N, LONG 74°30.0'W. What is the latitude and longitude of the point of arrival by Mercator sailing?

Correct Answer: Option C — LAT 32°33.0'N, LONG 64°46.0'W

Mercator sailing uses the difference in meridional parts to relate distance and course to change in longitude. For a 666-mile run at 135°T, the DLat is 471' and the DMP is 622.5. Solving for DLong yields 622.5' or 10°22.5'E, resulting in an arrival at 32°33.0'N, 64°46.0'W.