First of all, a quick recap of the terms, to know what we’re talking about and not get confused :
The terms lighthouse, lights and semaphore are often associated with maritime navigation, but they designate different equipment, each with a specific function. Here’s how they differ:
Headlights
- A lighthouse is a tower equipped with a powerful light, generally located on a strategic point (coast, islet, promontory) to guide ships at sea.
- It emits a light visible from very far away, often in the form of a rotating beam or flashes, enabling sailors to find their way at night or in conditions of low visibility.
- Lighthouses have distinct lighting characteristics (frequency and color of flashes), so they can be identified on nautical charts and when out at sea.
The lights
- Lights generally refer to the luminous signals used to guide sailors, but they are not necessarily associated with a large building such as a lighthouse.
- Lights can be found on dykes, jetties, harbors or even buoys at sea.
- Their main function is to mark a specific point (harbor entrance, danger, channel) or to provide an indication (red and green lights to indicate the sides of a channel, for example).
Semaphores
- A semaphore is an installation located on the coast, often high up, used for maritime surveillance and communications.
- Unlike lighthouses and lights, they do not produce light to guide ships.
- Semaphores are managed by maritime authorities and equipped with communications (radio, flags) to transmit information to ships (weather, traffic, warnings).
In a nutshell
Lighthouse: luminous building used as a navigational marker.
Lights: smaller-scale light signals, often on piers or buoys.
Semaphore: surveillance and communication post, without navigation lights.
