Chart Navigation & Plotting · Sailings — Plane Sailing
Steering 045°T, you run 20 nautical miles. What is the difference of latitude (in minutes) made good?
- A28.3' north
- B20.0' north
- C10.0' north
- D14.1' north✓ Correct
Explanation
dLat = distance × cos(course) = 20 × cos(45°) = 20 × 0.707 = 14.14 ≈ 14.1' of latitude. On a 045° course the northing and easting are equal, each 14.1'.
Authority: Bowditch (Pub. No. 9), plane sailing
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