605. The Light List shows that a navigational light has a nominal range of 18 miles and a height above water of 22 feet (6.7 meters). Your height of eye is 16 feet (4.9 meters) and the visibility is 2.0 miles. At which approximate range will you first sight the light?

The light's visibility is limited by its luminous range, which is reduced by poor visibility. The geographic range calculation determines the theoretical maximum distance based on height, but the light's actual range is 5.8 miles, as determined by the luminous range diagram for a nominal range of 18 miles in 2.0-mile visibility. Therefore, the light will first be sighted at approximately 5.8 miles.