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. Research continued through World War II to (1) reduce visibility by painting vertical surfaces to harmonize with the horizon and horizontal surfaces to blend with the sea, or (2) confuse identity and course by painting obtrusive patterns on vertical surfaces. Some camouflage methods served both purposes. American captains exercised less freedom of interpretation with these schemes (other than Measure 12 Modified) than their British Commonwealth counterparts applied to Admiralty camouflage schemes.

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. Rather than waste the large quantities of Standard Gray already in inventory and aboard ships, BuShips directed the issuance of a black tinting paste (5-BP) which when mixed in stated proportions with Standard Gray would yield a close approximation of 5-D, with issue of the new paint in pre-mixed form to follow. BuShips also issued Ship Camouflage Instructions (SHIPS-2), laying out 9 painting schemes to be used throughout the Navy. Rather than issue premixed quantities of the less-used new shades, Light Gray (5-L) and Ocean Gray (5-O), yards and supply depots were directed to issue an untinted base paint (5-U) together with a blue-black tinting material (5-TM) which when mixed according to instructions would turn 5-U into either Light or Ocean Gray.

The adoption of the new measures was very slow, however: as of late May the Navy's paint factories had yet to receive the ingredients needed for the new alkyd-based paints and only in late April had they received even the lampblack required for conversion paste 5-BP.

Measure 1A was an experimental scheme in overall Sea Blue, later adopted as Measure 11.

Measure 1B was another experimental scheme using overall Sapphire Blue.

Measure 1C similarly used Navy Blue, later adopted as Measure 21.

USS North Carolina wearing Measure 1.

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