also included a false bow wave to make it difficult for an enemy to estimate the ship's speed. Disguising heading and speed The historian Sam Willis argued that since Wilkinson knew it was impossible to make a ship invisible with paint, the "extreme opposite" was the answer, using conspicuous shapes and violent colour contrasts to confuse enemy submarine commanders. Willis pointed out, using the dazzle scheme as an example, that different mechanisms could have been at work. The contradictory patterns on the ship's funnels could imply the ship was on a different heading (as Wilkinson had said). The curve on the hull below the front funnel could seem to be a false bow wave, creating a misleading impression of the ship's speed. And the striped patterns at bow and stern could create confusion about which end of the ship was which. That dazzle did indeed work along these lines is suggested by the testimony of a U-boat captain: Motion dazzle In 2011, the scientist Nicholas E. Scott-Samuel and colleagues presented evidence using moving patterns on a computer that human perception of speed is distorted by dazzle patterns. However, the speeds required for motion dazzle are much larger than were available to First World War ships: Scott-Samuel notes that the targets in the experiment would correspond to a dazzle-patterned Land Rover vehicle at a range of , travelling at . If such a dazzling target causes a 7% confusion in the observed speed, a rocket propelled grenade travelling that distance in half a second would strike from the intended aiming point, or 7% of the distance moved by the target. This might be enough to save lives in the dazzle-patterned vehicle, and perhaps to cause the missile to miss entirely. World War I British Royal Navy In 1914, Kerr persuaded the First Lord of the Admiralty, Winston Churchill, to adopt a form of military camouflage which he called "parti-colouring". He argued both for countershading (following the American artist Abbott Thayer), and for disruptive coloration, both as used by animals. A general order to the British fleet issued on 10 November 1914 advocated use of Kerr's approach. It was applied in various ways to British warships such as , where officers noted approvingly that the pattern "increased difficulty of accurate range finding". However, following Churchill's departure from the Admiralty, the Royal Navy reverted to plain grey paint schemes, informing Kerr in July