Ship Camouflage Instructions
United States Navy
Ships - 2 
Revision 1
Bureau of Ships
September 1941

Discussion of Ship Camouflage


Reference 1:

Bureau of Construction and Repair Confidential Publication - "Handbook on Ship Camouflage" (Short Title - C and R. 4) 1937.

Reference 2:

Naval Research Laboratory Report H-1585, January 12, 1940, "Naval Camouflage, Tests at Sea, June to September, 1939," and references therein.

Reference 3:

Comdesbatfor Conf. Ltr. to Buships, 25 October 1940, S19 - Ser. 4888, "Camouflage of Destroyers - Low Visibility Paint."

Reference 4:

Comdesdiv. 17 Conf. Ltr. S19/FB17, 7 March 1941; FB17/S19/A16-3, 13 may 1941.

Reference 5:

Comdr. Lexington Air Group Conf. Ltr. CLAG/S19/(ts) (231) 6 June 1941.

Reference 6:

CinClant Ltr. S19/0581, 26 June 1941; 4Cl-41, 19 July 1941.

Reference 7:

CinCpac Ltr. S19/(50) Serial 01445, 13 September 1941.

Reference 8:

Naval Research Laboratory Report H-1598, March 14, 1940, "tests at Sea of February, 1940, in the Key West Area of the Visibility of Submarines and Transparency Measurements of Navigable Waters."  Comsubfor. Ltr. to Buships, FF4/A4-3/S19, 3 September 1940.

Results of Surface Ship Camouflage Experiments.

The results from earlier investigations of many aspects of surface ship camouflage by the Bureau of Construction and Repair were summarized in reference 1.  Investigations continued since that time are described in references 2 to 8.  The tests of references 2 and 3 culminated in the preparation of the First Edition of this booklet in January 1941.  Some of the more important facts on which the measures of the First Edition were used are:

  1. That a darker color is of low visibility to aerial observers in all type of weather because of sea background, but is relatively visible to surface observers because of sky background,  and yields some course deception to surface observers because shadows are not prominent.
  2. That a light color is of low visibility to surface observers in hazy and foggy weather.
  3. That a graded system produces some range deception.
  4. That bold dazzle camouflage was undesirable because of enhanced visibility.
  5. That unobtrusive dazzle camouflage yielded some deception without too great enhancement of visibility, but was limited in its application.
  6. That all camouflage is ineffective against the sun or other concentrated source of illumination.
  7. That camouflage for low visibility is more successful on small ships than on large ships.
  8. That wakes and smoke may neutralize any advantage gained by paint.

The measures of the First Edition employed three shades of gray, a Dark Gray, a Medium Gray, and a Light Gray (Standard Navy Gray of 1928 - 1940).  Subsequent experiments, references 4, 5, 6 and 7 led to the conclusion that the Dark Gray was too dark and the Light Gray too light., and that Blue Gray colors would be better than pure Gray colors.  The Blue Gray colors were selected, those of  Plate 12, and Measures 11 to 14 are based on them.  Another change was made based upon reference 6.  In the First Edition, Measure 2 was a graded system in which the hull of the ship was painted with three stripes, of Dark Gray at the waterline, Ocean Gray next above, and Light Gray above that.  This measure has been replaced by Measure 12 in which the dark color Sea Blue is carried from the waterline to the main deck, with Ocean Gray above this on the Superstructure masses and haze Gray on pole masts and small projections.  Measure 12 departed considerably from the original conception of a "graded" system, in which grading was carried out entirely on the hull. 

Experiment showed, references 5, 6 and 7, that certain measures of the First Edition were ineffective, namely, Measure 5, painted bow waves for speed deception, and Measures 6, 7 and 8, artifices of painting a ship to look like another ship of another class or type.  Accordingly, these measures have been omitted in the present revision.

Discussion of Measures 11, 12, 13 and 14.

Based on the preceding section the following remarks may be made concerning Measures 11, 12, 13 and 14.

Measure 11, Sea Blue, has not been tested.  However, its effectiveness may be said to be known approximately, and to be about the same as, or perhaps better than, the darker pure gray system which has been tested.

Measure 12, graded, has not been tested.  However, its effectiveness may be said to be known approximately and to be about the same as, or perhaps better than, a system not greatly different which has been tested by the Commander-in-Chief, Atlantic Fleet.  The system consisted of Sea Blue to the sheer line, Ocean Gray to the top of the high turrets including stacks and Haze Gray above, (reference 6).

Measure 13, Haze Gray, has not been tested, but inasmuch as it is intermediate in brightness between Ocean Gray and Standard Navy Gray of 1928 - 1940, its effectiveness may be said to be known approximately.

Measure 14, Ocean Gray, has been tested and its effectiveness is known.

Table 1 gives the approximate effectiveness of the various systems.  In fact, Table 1 gives about the only clear-cut conclusions which can be drawn in the light of present knowledge.

Table 1 - Approximate Effectiveness of Camouflage Measures.

Measure Least Visible Most Visible Deception
Measure 11
Sea Blue
Day: Aerial Observer Day: Surface Observer in
Clear of Hazy Weather
Course Deception
  Day: Against Dark
Cloud Bank
Day: Dark Smoke Screen
Night: When in Searchlight
Night: Moon Behind Surface
Measure 12
  A Compromise, Moderately
Low Visibility to Aerial and Surface Observers.
  Course and Range Deception and Ship 
Measure 13
Haze Gray
Day: Surface Observer in Hazy, Foggy Weather. Day: Aerial Observer  
  Night: No Moon. Night:  When in Searchlight.
Measure 14
Ocean Gray
Day: Surface Observer in Bright Sunny Weather.  
  Night: Moonlight

Discussion of Splotch Patterns.

A pattern of splotches for disturbing course estimation is completely ineffective in shadow.  Its effectiveness, if any, depends on the illumination and condition of observation.  These factors are so variable that no particular pattern can claim an advantage over any other pattern.  This is the reason that the directions in Chapter 3 for painting the spots are indefinite.  In general it is better to paint the lighter colors on areas which are usually in a shadow and the darker splotches on areas usually in the light.  The splotch patterns of  Plate 19 have not been tested.  Finally, it is true that although patterns of spots have been painted frequently on ships, there is no first hand information concerning their effectiveness.

Discussion of Measure 9 for Submarines.

Experiments off Key West, in the Canal Zone, and in Hawaiian waters with submerged submarines observed from the air, reference 8, showed in general that a dark color was the color of  lowest visibility, and in particular that a dark blue was slightly less visible than black.  The experiments were not sufficiently extensive to decide whether the slight difference was of essential importance.  It turned out that the earlier formulations of the dark blue paint, called "Pearl Harbor Blue", deteriorated and turned milky in a few weeks, whereas the black paint remained serviceable for several months.  Therefore, black paint is specified in Measure 9.  Improved formulas of Blue are being tested extensively in the fleet at present.  A special kind of colloidal painting for the purpose of reducing the visibility of the vertical surfaces (conning tower) of a submarine on the surface is being investigated by Comsublant and the Commandant First Naval District.

Discussion of Visibility of a Surface Ship at Sea.

The infinite variety of background against which ships are seen as a result of varying light and cloud effects will always make camouflage a controversial subject until a means is found to color a ship at will.  All that can be expected is the color which is effective most often against the observer whom it is most important to evade.  It is of interest to discuss a few well known general facts about the visibility of a ship at sea; a complete discussion of all cases would be tedious.  The visibility of a ship at sea depends on its contrast with the background, and this in turn depends on its contrast with the background, and this in turn depends on a number of factors, the more important of which are the color of  the ship and the background, the distance from the observer, the height of the observer above sea level and on the amount and character of the illumination.

Some of factors are illustrated in Plates 20 to 25, which give the appearance of a ship at various ranges to an observer at various altitudes above sea level.  Plates 20 to 24 are drawn to scale, and if looked at from a distance of about 30 feet are true to size.

As shown in Plate 20, to an observer not more than about 20 feet above sea level as on a submarine, practically the entire ship appears against the sky for all ranges above a few miles.  Hence for low visibility the ship should in general be a light color; a dark colored ship will be most visible but may give course deception because of the indistinctness of shadows.

Plates 20, 21 and 22 for altitudes of the observer of 20, 60 and 180 feet, respectively, illustrate the case of the observer on a surface ship and show that the ship appears against either a background of sea and sky, or of sky alone.  In this case a ship painted with some type of graded system may occasionally be less visible than a ship painted a solid color.  In addition a graded system may confuse the position of the waterline relative to the horizon and may yield range deception.

Plates 23 and 24 for altitudes of 1000 and 5000 feet, respectively, illustrate the case of the observer in the air.  he views the ship against the sea at all ranges.  Since the sea is fairly dark, except toward the sun and in the rare condition of mirror calm, the ship should be painted a dark color for the lowest visibility.

The effect of the relative bearing of the sun on the visibility of a light color ship and a dark color ship is illustrated in Plate 25.  The observer is at the center of the circle, and the altitude of the sun is taken to be between 20 degrees and 40 degrees.  The ships are assumed to be always broadside to the observer; this is a simple case.  The outside circle of ships appears against the horizon sky and hence refers to an observer near sea level.  The inside circle of ships appears against the water and hence refers to an observer in the air.  Toward, the sun both the light ship and dark ship are always darker than the background. whether the background is sky or water.

In the case of the sky background the dark ship is too dark at all bearings from  the sun.  Opposite the sun the light color ship may be too light, and if so, there is an intermediate sector in which the light ship may approximate the sky background in brightness and be of low visibility.  The width and position of this sector depends on the reflectivity (brightness) of the paint of the light color ship.

In the case of the sea background, in the sector away from the sun the dark ship may approximate the background brightness and be less visible than the light color ship.  There is another smaller sector, however, more or less toward the sun in which the dark ship is too dark and the light ship is the least visible.

More complex cases arise if the ship is not broadside to the observer.  Such cases being perfectly obvious would be tiresome to consider in detail, and similarly for cases of a partly cloudy sky.

Camouflage Paint.

All camouflage paint must be mat or dull, not glossy, and specification must be made of the maximum allowable amount of gloss.  Other optical qualities of the paint which require specification are its color and reflectivity.


A practical method of recording the color is by means of the Munsell Book of Color.*  The specification  that a certain is "Munsell PB 5/2" means that under daylight illumination the paint matches color and brightness the colored rectangle in the Munsell Book of Color on page "Purple Blue", row 5, column 2.  The spectrophotometric curves of all the color samples of the Munsell Book have been determined by the United States National Bureau of Standards, and the colors are therefore reproducible at any future time.  The Munsell notations of the camouflage colors are given in Table 2.

*Abridged Edition, 1929, Munsell Color Company, Inc., Baltimore, Maryland.  The Munsell color charts provide the best working standard available at present.

Table 2.    Data of Camouflage Colors

Name Formula Munsell Reflectivity Gloss
Deck Blue 20-B PB 3/4 7 Percent 14
Sea Blue 5-S PB 4/4 11 Percent 17.5
Ocean Gray 5-O PB 5/2 17 Percent 12
Haze Gray 5-H PB 6/2 28 Percent 12


The diffuse reflectivity of a painted surface for white light is a convenient and often used method of describing the lightness or darkness of the surface.  The reflectivity is the ratio of the total amount of white light diffusely reflected by the surface to the amount falling on the surface.  The reflectivity of a black surface is zero and of a white surface is 100 percent.  Magnesium carbonate has a reflectivity of about 98 percent and and is a practical standard of a non-glossy white.  The reflectivities of all the Munsell colors are tabulated on the unabridged  edition and therefore if a color is specified on the Munsell system its reflectivity is known automatically.  But in order to avoid looking up the Munsell table it is often desirable to give the reflectivities in addition to the Munsell notation.  The reflectivities of Deck Blue, Sea Blue, Ocean Gray and Haze Gray are listed in Table 2.  The reflectivity of a surface does not of course specify its color; for example on may have a red surface and a blue surface of the same reflectivity.  However, in dealing with a series of different shades of approximately the same color, as in the case of the camouflage colors, the reflectivity gives a fairly satisfactory numerical description of their lightness or darkness.  It is of interest to recall that Navy Standard Light Gray paint of the years 1928 - 1940 had a reflectivity of about 40 percent, and this was considerably lighter than the present Haze Gray.


A low gloss is desirable in camouflage paints to avoid highlights or bright reflections from the surfaces in sunlight or the beam of a searchlight.  Gloss is the property of a surface to reflect light SPECULARLY, which means like a mirror.  A surface which is not glossy is said to be MAT.  There is no accepted definition or scale of gloss; several arbitrary scales are available which depend upon the particular instrument selected to measure the gloss.  A convenient scale is based on the ratio of the amount of light reflected at an angle of 45 degrees from the surface in question to the amount reflected at the same angle from a surface of polished black glass.  On this scale the gloss values of the camouflage paints, freshly painted, are entered in Table 2.  The gloss value of a camouflage paint should be below about 20 percent to avoid undesirable bright reflections or "Highlight".  The Navy Standard Light Gray paint of 1928 - 1940 had a gloss of about 44 percent which weathered to about 28 after thirty days exposure.

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