Coast Guard Exams
Question 437Navigation General70% to pass

To measure distance on a Mercator chart between the parallels of LAT 34°30'N and LAT 31°30'N, which 30 mile scale should be used?

AI Explanation
The correct answer is C) 32°45'N to 33°15'N. On a Mercator chart, the 30 mile scale to use when measuring distance between the parallels of LAT 34°30'N and LAT 31°30'N is the scale centered on the middle latitude, which is 32°45'N to 33°15'N. This is because the Mercator projection distorts distances, and using the scale centered on the middle latitude provides the most accurate measurement. The other options are incorrect because they do not correspond to the middle latitude between the given parallels. Option A is too far north, option B is slightly too far north, and option D is too far south.

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