550. The Light List indicates that a light has a nominal range of 14 miles and is 26 feet high. If the visibility is 4 miles and your height of eye is 20 feet, at what approximate distance will you sight the light?

The light's visibility is limited by both atmospheric conditions and Earth's curvature. With a nominal range of 14 miles and a visibility of 4 miles, the actual luminous range is 7.5 miles. This distance is less than the geographic range (approximately 11.2 miles), so the light will be sighted at 7.5 miles.