The Alderney Race, a notorious strait of water between Alderney and Cap de la Hague in France, includes the strongest tidal streams in Europe. These are caused by the tidal surge from the Atlantic building up in the cul de sac of the gulf of St. Malo with the only escape in the north east corner between Alderney and Cap de la Hague. Water flows through at speed at high tide and is sucked back down through as the tide recedes. An uneven sea bed adds to the turbulence with a number of hazardous rocks located within a few miles of the lighthouse.
Alderney Lighthouse—sited on Quénard Point, to the north-east of the Island—rises 32 metres and is painted white with a central black band to make it more visible to shipping during the hours of daylight. The former keepers' dwellings adjoin the tower, as do the service rooms, and the station is surrounded by a white wall.
Alderney Lighthouse was automated in 1997 with the keepers leaving the lighthouse on 1 October.
The navigation light system comprises of four LED lanterns operating as two synchronised pairs, with only one pair in operation at any time. The first order four panel catadioptric rotating optic was decommissioned in 2016-17.
The lighthouse is now monitored and controlled from Trinity House’s Planning Centre in Harwich, Essex.