Isophase (Iso)

A light where the duration of light and darkness are equal.

Isophase describes a navigational aid that emits a light signal with equal periods of light and darkness. This results in the light appearing on for the same time as it is off, creating a distinctive flashing pattern that helps mariners identify the aid and determine their position.

Abbreviation

Iso

Class of Light

Isophase

Illustration

Period Shown