USS Charles S Sperry, June 1944

Dazzle did not conceal the ship but 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 is in view; and it would be equally difficult to estimate whether the observed vessel is moving towards or away from the observer's position.

source: http://en.wikipedia.org/wiki...