In A Nutshell
In World War I and, to a lesser extent, World War II, the British Admiralty coated their warships with dazzling optical illusions to disorient enemy attackers.
The Whole Bushel
In 1914, an embryologist named John Graham Kerr approached Winston Churchill and proposed a new way to camouflage Britain’s ships. Taking his inspiration from animals like the zebra and giraffe, he suggested that instead of trying to conceal their ships, they make them so glaringly conspicuous that it would be nearly impossible to target them.
The trick was in the paint, which formed optical illusions along the hulls of the ships. The goal was to make it so disjointed, so visually confusing, that rangefinders wouldn’t be able to get a fix on the ship’s location, size, and speed. See, the rangefinders used to pinpoint enemy ships at the time worked by creating two half-images of a target; when the operator maneuvered the half-images into a single, unbroken image, he could calculate the ship’s distance, allowing them to calibrate the guns for an accurate shot.
But if you looked at a ship with dazzle camouflage, the two half-images still ended up looking like a mismatch, even when they were perfectly aligned. With their patterns of zigzags, spirals, and complex geometric shapes, the ships didn’t look like ships anymore; all the distinguishing features normally used to identify a ship’s orientation—mainly the stern and the bow—were lost in the illusion.
The trick was used sparingly for several years, but when German submarines began picking off merchant ships in 1917, the British Admirality put out a blanket order to have trading vessels painted with dazzle camouflage—4,000 ships were given a fresh coat of glitter and mayhem. Later that year, the first warship was given the same treatment, and hundreds more got a coating of dazzle camouflage before the war finally ended.
Every ship was given a different pattern. The Admiralty called in a creative army of artists, sculptors, and designers to create each design. While some were just crazy jumbles of lines and shapes, others were full-on optical illusions, creating such effects as making the center of the ship appear higher than either side.
In 1918, the US Navy got into the game and adopted dazzle camouflage for their own ships. They used it extensively on aircraft carriers and battleships in World War II, but eventually rangefinder technology caught up to their shenanigans and the technique lost its effectiveness.
But was it ever effective to begin with? The Admiralty made it a point to use a different paint scheme on every single ship so the enemy couldn’t learn to use the patterns to identify specific classes of ship. As a result, it was hard to tell what worked and what didn’t. There was no standard; one ship could be painted bright blue with red spirals, and another might be painted with intersecting black and white bars. If one of those went down, it could have been because of the colors, or the pattern, or just because the enemy got lucky. There were too many factors involved to fairly evaluate it.
Regardless, both the US and the British continued using dazzle paint through the end of the Second World War. Germany even tried it a few times, but that didn’t turn out too well.