The Light List shows that a navigational light has a nominal range of 22 miles and a height above water of 48 feet (14.6 meters). Your height of eye is 35 feet (10.7 meters) and the visibility is 20.0 miles. At what approximate range will you first sight the light?

Correct Answer: Option C — 14.7 nm

Calculate the geographic range using the formula 1.17 times the square root of the height of eye (35ft) plus 1.17 times the square root of the light's height (48ft). This yields 6.9 + 8.1 = 15.0 nm. Since visibility is 20 nm, the light is sighted at the geographic range of 14.7-15.0 nm.