Chart Navigation & Plotting · Mercator Projection
On a Mercator chart, a rhumb line (line of constant course) appears as:
- AA curve concave toward the nearer pole
- BA straight line✓ Correct
- CA great circle
- DA parabola
Explanation
The defining property of the Mercator projection is that rhumb lines plot as straight lines, so a course of constant true direction can be drawn and measured with parallel rulers. A great circle, by contrast, plots as a curve.
Authority: Bowditch, American Practical Navigator (Pub. 9), Mercator projection
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