A vessel at LAT 10° 22.0' S, LONG 7° 18.0'...

Question 1 of 2707066636eea28f7522a1c51b7bb

A vessel at LAT 10° 22.0' S, LONG 7° 18.0' E, heads for a destination at LAT 6° 52.0' N, LONG 57° 23.0' W. Determine the true course and distance by Mercator sailing.

Back

Question 1 of 27070

A vessel at LAT 10° 22.0' S, LONG 7° 18.0' E, heads for a destination at LAT 6° 52.0' N, LONG 57° 23.0' W. Determine the true course and distance by Mercator sailing.

🔍 Key Concepts

• Mercator sailing uses meridional parts to account for the change of latitude on a Mercator projection • Compute difference of latitude (DLat) and difference of longitude (DLo), remembering N/S and E/W signs • Use departure and the relationship between DLo, latitude, and course to find the course, then distance from DLat and course

💭 Think About

• First, determine the total change in latitude from 10° 22.0' S to 6° 52.0' N: what is the combined DLat in minutes? • Then, convert both latitudes to meridional parts (from tables or formulas). What is the difference in meridional parts (DMP)? • How do DLo, DMP, and course relate in Mercator sailing, and once you find the course, how can you use DLat and course to get the distance?

✅ Before You Answer

• Be sure to treat south latitude as negative and north latitude as positive when finding DLat • Convert all angles to minutes of arc or decimal degrees consistently before using formulas • Check that the course you get is in the correct quadrant (NW, NE, SE, SW) based on starting and ending lat/long positions