World War II ship camouflage measures of the United States Navy

In 1935, the United States Navy Naval Research Laboratory began studies and tests on low visibility ship camouflage.

[1] With the likelihood of the United States entering the war, and after experiments with various paint schemes conducted in association with the 1940 Fleet Problem (exercise), the Bureau of Ships (BuShips) directed in January 1941 that the peacetime color of overall #5 Standard Navy Gray, a light gloss shade with a linseed oil base, be replaced with matte Dark Gray, #5-D, a new paint formulation with a synthetic alkyd resin base.

USS Minneapolis wearing a variant of Measure 8, 1943 By the summer of 1941 it had become apparent that Dark Gray (5-D) was unacceptably visible under all conditions,[8] and the "conversion" 5-D made from prewar #5 was also too glossy and prone to chipping and peeling; meanwhile Pacific Fleet experiments with new colors Sea Blue and Sapphire Blue were deemed successful.

[10] The tinting paste was altered to contain somewhat less black and more blue than before; this meant that Ocean Gray also became somewhat more bluish in cast at this time and all the 5-series paint colors now were categorized as Munsell 5 Purple-Blue.

Until 1945 all USN "gray" and almost all "blue" shades were produced using this same blue-black tint (5-TMa), so that the paints represented different tones of what was effectively a single blue-gray hue.

"[16] There were no specific instructions on the positioning or shape of the splotches, which were left up to individual captains, yards or maintenance facilities, and the recommended size was frequently disregarded, so that no two ships looked alike.

[6] Asiatic Fleet: The Asiatic Fleet, based in distant Manila, was unable to obtain the new paint colors and so in November painted its ships overall in a color procured from local sources midway between Sea Blue and Ocean Gray, dubbed "Cavite Blue."

Within the first six months of combat, the United States Navy modified Measures 11 and 12 to meet the needs of Pacific Ocean operations.

[22] According to a contemporary report, "The color of the foliage [in the vicinity of Bougainville] was surprisingly high in key, a brilliance that would have been unbelievable except for the very same observations made on first arrival in the Solomons group.

Initial Admiralty disruptive camouflage schemes employed polygons of multiple shades of gray, blue and green so at least two of the colors would blend with background sea or sky under different light conditions.

Artist Everett Warner, who had headed the design section of Navy Camouflage during the First World War, returned to that post during the Second.

On the basis of Warner's interpretations of recent Admiralty experience, BuShips issued a supplement to SHIPS-2 in March 1943 laying out multiple dazzle patterns under Measures 31 (dark), 32 (medium) and 33 (light) to conceal identity and confuse submarine torpedo fire control.

USS Flint wearing Measure 33, Design 22D In January 1945 BuShips revised its paint formulations due to a shortage of blue pigment, and the realization that tone was far more important than hue in camouflage effect, eliminating the blue-purple shades which had characterized nearly all Navy ship colors whether called "blue" or "gray."

[26] Ironically, the Atlantic Fleet did not get the memo, and during 1945 ships scheduled for Pacific transfer were repainted in dazzle, only to be painted again in Measure 21 or 22 on arrival at the West Coast or Hawaii.