The Light List shows that a navigational light has a nominal range of 12 miles and a height above water of 25 feet (7.6 meters). Your height of eye is 30 feet (9.1 meters) and the visibility is 0.5 mile. At what approximate range will you first sight the light?

Correct Answer: Option A — 1.4 miles

Visibility is the limiting factor here. The geographic range is 12.0 nm, but the actual visibility is only 0.5 miles. Because the light's intensity cannot overcome the 0.5-mile atmospheric obstruction, the light will only be sighted at the distance of the prevailing visibility, approximately 1.4 miles.