The evolution of preventing any lights from being seen from outboard of the ship during wartime. In general blackout screens were rigged over doors and hatches leading onto the weather decks and the dead lights lowered over all scuttles.
Yindaleko yokuthintela nakuphina ukukhanya ekubeni kubonakale ngaphandle kwenqanawa ngexesha lemfazwe. Iizibonisi ezimnyama zazixhotyiswa ngeemasti neseyile emacangweni nakwizivalo zenqanawa ezikhokelela kwiidekhi zemozulu kwaye izibane ezifileyo zazihliselwa kuzo zonke izikroba ezineziciko.