The lights on many lighthouses and lightvessels were extinguished during the Second World War, but not all lights were extinguished outright. Trinity House worked extensively with the Admiralty to decide which lights should be merely dimmed, so as to aid navigation for Britain's merchant and fighting ships.
Trinity House Pilots worked throughout the nights to get ships into safe ports, and Trinity House Tenders worked to help clear minefields, evacuate the occupied Channel Islands and take part in the events of D-Day.
Many lighthouses on enemy flight paths were painted with camouflage paint. Many Keepers on Lighthouses, and crewmen on Lightvessels lost their lives, and are commemorated on a memorial in Trinity Square in London.