Chart Navigation & Plotting · Great Circle Sailing
Compared with a rhumb line between the same two points (not on the equator or a single meridian), a great-circle track is:
- AAlways longer
- BThe same length
- CThe shortest distance, but requires continuous course changes✓ Correct
- DA straight line on a Mercator chart
Explanation
A great circle is the shortest path over the earth's surface, but its track crosses meridians at continuously changing angles, so the course must be altered regularly (often sailed as a series of rhumb-line legs between waypoints).
Authority: Bowditch (Pub. No. 9), great-circle sailing
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