The Light List indicates that a light has a nominal range of 14 miles and is 42 feet (12.7 m) high. If the visibility is 16 miles and your height of eye is 20 feet (6.1 m), at which approximate distance will you sight the light?

Correct Answer: Option D — 12.8 miles

Geographic range is calculated using Bowditch Table 12: 1.17 times the square root of 42 plus 1.17 times the square root of 20, which equals 12.8 nautical miles. Since the luminous range (16 miles) exceeds this geographic range, the light is first sighted at its geographic limit.