Ship camouflage

Counterillumination, to hide a darkened ship against the slightly brighter night sky, was trialled by the Royal Canadian Navy in diffused lighting camouflage.

Vegetius records that Julius Caesar's scout ships were painted bluish-green when gathering intelligence along the coast of Britain during the Gallic Wars.

He intended it not to make ships invisible, nor even to cause the enemy to miss his shot, but to deceive him into taking up a poor firing position.

[1] Vegetius writing in the 4th century says that "Venetian blue" (bluish-green, the same color as the sea) was used in the years 56–54 BC during the Gallic Wars, when Julius Caesar sent his speculatoria navigia (scout ships) to gather intelligence along the coast of Britain.

[13] British ships began being painted gray in 1903; lighter shades were preferred to minimize solar heating in warmer climates.

Early in the First World War, the zoologist John Graham Kerr advised Winston Churchill to use disruptive camouflage to break up ships' outlines, and countershading to make them appear less solid,[14] following the American artist Abbott Handerson Thayer's beliefs.

[15][16] Kerr was not an effective political campaigner, and his ideas were abandoned on Churchill's departure from the Admiralty, while his postwar legal action to claim credit for ship camouflage failed.

[17] His successor, the marine artist Norman Wilkinson, successfully promoted the idea that Kerr's camouflage sought invisibility rather than image disruption.

[18] Under Wilkinson, the Admiralty researched and issued a large number of "razzle-dazzle" designs, which became known simply as "dazzle", to counter the threat from submarines.

[21] Deceptive measures other than dazzle included the fitting of anti-rangefinder baffles to the masts and yards of battleships such as HMS Emperor of India in 1917.

[26] In 1915 and 1916, the Germans further made use of commerce raiders, converted freighters with hidden weapons and long range, able to slip through the British blockade and then attack shipping as far away as the south Atlantic.

This bold contrast on a horizontal line near the horizon reduced visibility to surface observers and created the illusion of greater range.

This camouflage was considered most effective for gunnery engagements with surface units or shore batteries in areas where aerial observation was unlikely.

It was worn by shore bombardment ships in the Pacific from late 1944 after the destruction of Japanese naval aviation capability at the Battle of the Philippine Sea.

[34] In 1935, the United States Navy Naval Research Laboratory began studies and tests on low-visibility camouflage for ships.

Measures making cruisers resemble destroyers were discontinued after causing station-keeping confusion among ships operating in formation.

Haze gray was found to provide reasonable protection in the widest range of conditions, and became a standard US Navy paint scheme after World War II.

On the advice of United States aviators the blue color was darkened and used extensively in the western and southern Pacific from mid-1942 through 1945 to minimize detection and identification by enemy aircraft.

Mountbatten observed a Union-Castle Liner disappear from convoy during an autumn sunset because of the company's unusual lavender-mauve-gray hull color.

Mountbatten reasoned the color would be effective camouflage during dawn and dusk periods, and devised a similar shade by mixing medium gray with a small amount of venetian red.

Admiralty camouflage schemes promulgated in 1941 were not universally adopted because of difficulties with operating schedules and shortages of some paint pigments.

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

[34][14] Captain-class frigate were delivered painted white with a pattern of sea blue and light gray in an American Western Approaches variant.

[37] The Admiralty's informal approach changed when a branch of the Naval Research Laboratory was established at Leamington Spa under Commander James Yunge-Bateman to test ship camouflage schemes experimentally.

Painted models were floated in a large tank and examined against different backgrounds, using theater lamps to simulate varying lighting conditions.

On suggestion by Professor Leslie Cromby, lead oxide was applied to the hull, enabling it to become black on application of a solution of sulphite and sea water for night operation.

For day sailing, a solution of hydrogen peroxide and sea water would be applied, producing sulphate and returning the hull to a white colour desirable for daytime conditions.

In special tactical situations, camouflage could be improvised, as when the battleships Yamato and Musashi had their decks blackened with a mixture of soot to help them hide while passing through the San Bernardino Strait at night in the October 1944 Battle of Leyte Gulf.

[51] By 1945, with the remnants of the Japanese Navy seeking to hide from American air power, its battleships were painted in a variety of camouflage measures.

However, camouflage may have helped United States warships avoid hits from Vietnamese shore batteries which used optical rangefinders.