Chart Navigation & Plotting · Distance — Dipping a Light
A light charted at 121 feet, with your height of eye 16 feet, will first appear (dip up) at a range of (1.17(√H + √h)):
- A23.40 NM
- B14.04 NM
- C12.87 NM
- D17.55 NM✓ Correct
Explanation
Dipping range = 1.17(√121 + √16) = 1.17(11 + 4) = 1.17 × 15 = 17.55 NM. The range at which the light first appears gives a distance-off LOP.
Authority: Bowditch (Pub. No. 9), Dipping Distance
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