Dazzle Camouflage - Mechanism

Mechanism

Further information: Camouflage: dazzle patterning

At first glance dazzle seems an unlikely form of camouflage, drawing attention to the ship rather than hiding it, but this technique was developed after the Allied Navies were unable to develop effective means to disguise ships in all weathers.

John Graham Kerr, who first applied the principle to British warships in WW I, outlined the principle in a letter to Winston Churchill in 1914 explaining that disruptive camouflage sought to confuse not to conceal, "It is essential to break up the regularity of outline and this can be easily effected by strongly contrasting shades ... a giraffe or zebra or jaguar looks extraordinarly conspicious in a museum but in nature, especially when moving is wonderfully difficult to pick up."

While dazzle did not conceal a ship, it made it difficult for the enemy to estimate its type, size, speed and heading. The idea was to disrupt the visual rangefinders used for naval artillery. Its purpose was confusion rather than concealment. An observer would find it difficult to know exactly whether the stern or the bow was in view; and it would be equally difficult to estimate whether the observed vessel was moving towards or away from the observer's position.

Rangefinders were based on the coincidence 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 intended to make estimation of the ship's speed difficult.

Dazzle camouflage was accepted by the Admiralty, even without practical visual assessment protocols for improving performance by modifying designs and colours. The dazzle camouflage strategy was adopted by other navies. This led to more scientific studies of colour options which might enhance camouflage effectiveness. Broken colour systems which present units so small as to be invisible as such at the distances considered are neither advantageous nor detrimental to the dazzle effect; the visibility of the camouflaged vessel at a given distance would depend entirely upon such scientifically measurable factors as the mean effective reflection factor, hue and saturation of the surface when considered at various distances.