The American artist Abbott Handerson Thayer had developed a theory of camouflage based on countershading and disruptive coloration, which he had published in the controversial 1909 book Concealing-Coloration in the Animal Kingdom.

Seeing the opportunity to put his theory into service, Thayer wrote to Churchill in February 1915, proposing to camouflage submarines by countershading them like fish such as mackerel, and advocating painting ships white to make them invisible.

Claimed effectiveness: Artist's conception of a U-boat commander's periscope view of a merchant ship in dazzle camouflage (left) and the same ship uncamouflaged (right), Encyclopædia Britannica, 1922.

The conspicuous markings obscure the ship's heading.

However, in the same letter, Kerr also called for countershading, the use of paint to obliterate self-shading and thus to flatten out the appearance of solid, recognisable shapes.

For example, he proposed painting ships' guns grey on top, grading to white below, so the guns would disappear against a grey background.

He had a warm welcome from Kerr in Glasgow, and was so enthused by this show of support that he avoided meeting the War Office, who he had been intending to win over, and instead sailed home, continuing to write ineffective letters to the British and American authorities.

The marine artist and Royal Naval Volunteer Reserve officer Norman Wilkinson, agreed with Kerr that dazzle's aim was confusion rather than concealment, but disagreed about the type of confusion to be sown in the enemy's mind.

Dazzle camouflage, also known as razzle dazzle (in the U.

S.) or dazzle painting, was a family of ship camouflage used extensively in World War I, and to a lesser extent in World War II and afterwards.

At first glance, dazzle seems an unlikely form of camouflage, drawing attention to the ship rather than hiding it.