Casquets lighthouses

Perched on Les Casquets rocks off Alderney in the Channel Islands, a lighthouse stands to warn ships of the surrounding shoals. It forms part of the historic light station that has been operational since the 1720s.

The present tower is a cylindrical stone structure crowned with a balcony and red lantern. Its tower is painted in white and red horizontal bands, with the lantern also finished in red. The tower rises 23 m above its base, giving the light a focal height of 37 m. A second‑order 700 mm rotating lens projects a flash of five white lights every 30 seconds, visible to a range of 18 nmi. The lantern houses an LED source delivering an intensity of 452,000 candela.

Construction of the original light station began in the early 1720s, with the stone towers completed in 1723. The lights were first exhibited on 30 October 1724, originally using coal fires in three separate towers named St Peter’s, St Thomas and Dungeon. Thomas Le Cocq built the towers under a licence from Trinity House and operated them on a lease. The surviving tower was fully automated in 1990.

The lighthouse remains an active aid to navigation and is maintained by Trinity House.

Light and tower

The light has a focal height of 32692860 metres. The Admiralty list of lights numbers it A1532.