Chart Navigation & Plotting · Sailings — Plane Sailing Course and Distance
A short passage gives a difference of latitude of 40' N and a departure of 30' E. The plane-sailing course and distance are:
- A037°T, 70 NM
- B053°T, 50 NM
- C037°T, 50 NM✓ Correct
- D045°T, 50 NM
Explanation
Course = arctan(departure ÷ dLat) = arctan(30 ÷ 40) = 36.87° → N37°E = 037°T. Distance = √(40² + 30²) = √2500 = 50 NM.
Authority: Bowditch (Pub. No. 9), Plane Sailing
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