British preparation for night action concentrates on avoiding friendly fire. Each ship displays four horizontal lights at the head of its mizzen mast and an illuminated white ensign. White is easier to distinguish from the French tricolour in darkness than the other ensigns the Royal Navy could use. As the prospect of a night battle becomes certain, crews add further identification flags and illuminate them. These are practical recognition measures developed through experience, without a fully organized night-fighting doctrine.
Notable Point · 53:02-54:24
Recognition lights prepare the British fleet for darkness
Four horizontal mast lights and illuminated white ensigns help British ships identify one another during the night attack.