During the Great War, navies learned that they couldn’t hide their ships through camouflage, because the background shifted so drastically with every change in the weather — but they could razzle-dazzle enemy range-finders with what painter Norman Wilkinson called dazzle painting:
The rangefinders were based on the co-incidence principle with an optical mechanism, operated by a human to compute the range. The operator adjusted the mechanism until two half-images of the target lined up in a complete picture. Dazzle was intended to make that hard because clashing patterns looked abnormal even when the two halves were aligned. This became more important when submarine periscopes included similar rangefinders. As an additional feature, the dazzle pattern usually included a false bow wave to make estimation of the ship’s speed difficult.
