A light characteristic is a coded description displayed on a nautical chart under the chart symbol for a lighthouse, lightvessel or sea mark with a light on it, to indicate how that light is recognised visually and audibly.

An example of a light characteristic is Gp Oc(3).10s 15m 10M. This indicates the light is a Occulting Group of 3, every 10 seconds, 15 metres tall and visible for 10 nautical miles.

The following chart describes some of the different types of light characteristics: