Projectors were mounted on temporary supports attached to the hull and the prototype was developed to include automatic control of brightness using a photocell.

Diffused lighting camouflage was explored by the Royal Canadian Navy (RCN) and tested at sea on corvettes during World War II, and later in the armed forces of the UK and the US.

[1] An equivalent strategy, known to zoologists as counter-illumination, is used by many marine organisms, notably cephalopods including the midwater squid, Abralia veranyi.

[2] In 1940, Edmund Godfrey Burr, a Canadian professor at McGill University,[3] serendipitously stumbled on the principle of counter-illumination, or as he called it "diffused-lighting camouflage".

With these, he found that aircraft flying without navigation lights remained readily visible as silhouettes against the night sky, which was never completely black.

[1] Parallel trials of the Canadian diffused lighting equipment were carried out in March 1941 by the Royal Navy on the corvette HMS Trillium in the Clyde approaches.

[1] The US Navy trialled an automatic system made by General Electric[a] of New York on the supply ship USS Hamul, but halted research in 1942.

Each ship's diffused lighting system was tested systematically in St Margaret's Bay, and then trialled when actually escorting Atlantic convoys in 1943.

Experimentally, the diffused lighting reduced the ships' visibility by up to 70%, but at sea the electrical equipment proved too delicate, and frequently malfunctioned.

However the attack failed, as a wrong signal sent from shore alerted the submarine's commander, Kapitänleutnant Rolf Schauenburg; U-536 dived and escaped.

[1] Following the Allied victory in the Battle of the Atlantic – through long-range aircraft, radar, code decryption, and better escort tactics – the need to camouflage ships from submarines greatly decreased, and diffused lighting research became a low priority.

[1] An American version, "Yehudi", using lamps mounted in the aircraft's nose and the leading edges of the wings, was trialled in B-24 Liberators, Avenger torpedo bombers and a Navy glide bomb from 1943 to 1945.