Buoys and Lights

Question 1

Define Geographical Range.

Answer 1

Geographical range is the maximum distance at which a light can reach an observer as determined by the height of eye at the observer, the height of the structure, and the curvature of the earth.

Question 2

Define Luminous range.

Answer 2

The luminous range is the maximum distance at which a light can be seen, determined only by the intensity of the light and the visibility at the time. It takes no account of elevation, observer’s height of eye, or curvature of the earth.

Question 3

Define Nominal range.

Answer 3

The nominal range is normally the luminous range for a meteorological visibility of 10 miles.