266. The Light List shows that a navigational light has a nominal range of 15 miles and a height above water of 40 feet (12.2 meters). Your height of eye is 25 feet (7.6 meters) and the visibility is 5 miles. At about what range will you FIRST sight the light?

The limiting factor for visibility is the lesser of the geographic range and luminous range. With 5-mile visibility, a light with a nominal range of 15 miles has a luminous range of approximately 9.5 miles, which is less than the geographic range, making 9.5 miles the correct answer.