In relatively recent appearance, at least in their architecture and modern technology, lighthouses are located on a coastal networking sites sometimes very vulnerable and require careful maintenance.
Today, often automated, and competition from sophisticated tracking systems (such as GPS ), few remain guarded and become more vulnerable to a gradual degradation.
By international convention, the colors and the light emitted from the headlights rhythms carry information.
And red signals danger and white indicates coastal shipping to follow.
As for the lights, depending on the location of the person who receives it defines three areas : red, to avoid; White, viable; green, natural shelter possible.