One of Germany’s most feared and effective weapons during World War I was its fleet of submarines—known as U-boats—that roamed the Atlantic, sneaking up underwater on British merchant ships and destroying them with torpedoes. During the course of the war, they sank more than 5,700 vessels, killing more than 12,700 non-combatants in the process.

The British weren’t sure what to do. Camouflage worked in land warfare, but it was another matter for an object as big as a cargo ship to blend into the ocean, especially when smoke was billowing from its stacks.

But a Royal Navy volunteer reserve lieutenant named Norman Wilkinson—a painter, graphic designer and newspaper illustrator in his civilian life—came up with a radical but ingenious solution: Instead of trying to hide ships, make them conspicuous.

By covering ships’ hulls with startling stripes, swirls and irregular abstract shapes that brought to mind the Cubist paintings of Pablo Picasso or Georges Braque, one could momentarily confuse a German U-boat officer peering through a periscope. The patterns would make it more difficult to figure out the ship’s size, speed, distance and direction.

Wilkinson’s idea was a startling contrast to those of other camouflage theorists. American artist Abbott Thayer, for example, advocated painting ships white and concealing their smokestacks with canvas in an effort to make them blend into the ocean, according to Smithsonian.

Dazzle camouflage, as Wilkinson’s concept came to be called, “appeared to be counter-intuitive,” explains Roy R. Behrens, a professor of art and Distinguished Scholar at the University of Northern Iowa, who writes “Camoupedia,” a blog that’s a compendium of research on the art of camouflage. “For Wilkinson to come up with the ideas of redefining camouflage as high visibility, as opposed to low visibility, was pretty astonishing.”

As Peter Forbes writes in his 2009 book Dazzled and Deceived: Mimicry and Camouflage, Wilkinson—who commanded an 80-foot motorboat used for minesweeping off the British coast—apparently was inspired during a weekend fishing trip in the Spring of 1917. When he returned to the Royal Navy’s Devonport dockyard, he went straight to his superior officer with his idea.

“I knew it was utterly impossible to render a ship invisible,” Wilkinson later recalled, according to Forbes’ book. But it had occurred to him that if a black ship was broken up with white stripes it would visually confuse the enemy.

“The idea had precedent in nature, with the pattern disruption in the coloration of animals,” Behrens says. As a study by British and Australian researchers nearly a century later would reveal, zebras’ stripes seem to serve that purpose, turning a herd into what appears to be a chaotic mess of lines from a distance, and making it tougher for lions and other predators to intercept them.

As Behrens explains, when submerged, the Germans’ only way of sighting a target was through the periscope, which they could only poke through the water for a fleeting moment because of the risk of being detected. They had to use that tiny bit of visual data to calculate where in the water to aim the torpedo so that it would arrive at that spot at the same moment as the ship they were trying to sink.

Wilkinson’s camouflage scheme was designed to interfere with those calculations, by making it difficult to tell which end of the ship was which, and where it was headed. With torpedoes, there wasn’t much margin for error, so if the dazzle camouflage threw off the calculations by only a few degrees, that might be enough to cause a miss and save a British ship.

“It was exploiting the limited view of the periscope,” Behrens explains.

An art-lover today might assume that dazzle camouflage was the brainchild of a cubist painter, not someone such as Wilkinson, a representational artist who liked to paint ships and seascapes. Claudia Covert, a special collections librarian at the Rhode Island School of Design and author of a 2007 article on Dazzle camouflage in Art Documentation: Journal of the Art Libraries Society of North America, says that Wilkinson “was probably aware of these contemporary movements—Cubism, Futurism, and Vorticism. In fact, one of the Vorticist painters, Edward Wadsworth, oversaw ships being dazzled in Liverpool during the war.”

Additionally, “you have to remember that Wilkinson was not only a seascape painter but also a poster designer,” Behrens says. “So he had to work with abstract forms, colors and shapes.”

Though the British Admiralty probably didn’t include too many modern art enthusiasts, the losses from U-boat attacks were so devastating that they soon authorized Wilkinson to set up a camouflage unit at the Royal Academy in London. He recruited other artists, who were given Naval Reserve commissions, and they got to work.

Wilkinson made models of ships on a revolving table and then viewed them through a periscope, using screens, lights and backgrounds to see how the dazzle paint schemes would look at various times of day and night. He used one of those models to impress a visitor, King George V, who stared through the periscope and guessed that the model ship was moving south-by-west, only to be surprised to discover that it was moving east-by-southeast.

By October 1917, British officials were sufficiently convinced of dazzle’s effectiveness that they ordered that all merchant ships should get the special paint jobs, according to this 1999 article by Behrens.

At the request of the U.S. government, Wilkinson sailed across the Atlantic in March 1918 and met with Secretary of the Navy Franklin D. Roosevelt, and then helped to set up a camouflage unit headed by American impressionist painter Everett Warner.

By the end of the war, more than 2,300 British ships had been decorated with dazzling camouflage. How successful dazzle actually was in thwarting U-boat attacks isn’t clear. As Forbes explains, a postwar commission concluded that it probably only provided a slight advantage.

“When the US Navy adopted Wilkinson's scheme for both merchant and fighting ships there is statistical evidence to support Wilkinson's technique,” Forbes says. A total of 1,256 merchant and fighting ships, were camouflaged between March 1 and November 11, 1918. Ninety-six ships over 2,500 tons were sunk; of these only 18 were camouflaged and all of them were merchant ships. "None of the camouflaged fighting ships were sunk,” he says

“It’s important to remember that ships didn’t just rely upon dazzle camouflage for protection from U-boats,” Behrens explains. “It was used in combination with tactics such as zig-zagging and traveling in convoys, in which the most vulnerable ships were kept in the center of the formation, surrounded by faster, more dangerous ships capable of destroying submarines.” The synergy of those measures was “wonderfully effective,” he says.

Dazzle camouflage was resurrected by the U.S. during World War II, and was used on the decks of ships as well, in an effort to confuse enemy aircraft. Today’s electronic surveillance technology makes dazzle pretty much obsolete for protecting ships, but as Forbes points out, the concept of visually disruptive patterns is still used in military uniforms.