Hiding Ships with Paint 



How protective coloring causes Fritz much 

 waste of torpedoes. It is camouflage at its best 



Bv Robert G. Skerrett 



THE gun afloat, whether upon a naval 

 craft or an armed merchantman, 

 drives the submarine to cover be- 

 neath the waves when it approaches its 

 prey close enough to discharge the tor- 

 pedo. The U-boat commander must, 

 therefore, keep track of his moving target. 

 At best, a periscope is a poor substitute 

 for the naked eye or the binocular vision 

 made possible by good field glasses. The 

 periscope is one-eyed, and this entails very 

 definite and unsatisfactory limitations. 

 These facts must be kept in mind in 

 order to evaluate the real purpose of ma- 

 rine camouflage. 



Marine camouflage differs radically 

 from camouflage ashore where the charac- 

 ter of the background facilitates conceal- 

 ment. It is a simple thing to cloak a gun 

 with a screen of foliage or to mottle it 

 with paint so that its contours disappear. 

 The ship afloat, except through the 

 agency of a smoke screen, cannot veil its 

 identity. Under certain conditions of 

 light, the vessel stands vividly silhou- 

 etted against the sky, and even when the 

 atmospheric contrast is not so sharp, the 

 ship can be seen rather distinctly though 

 painted a single tone of gray. 



Atmospheric gray and paint-brush gray 

 are two fundamentally different things so 

 far as vision or visibility is concerned. 

 The latter is the product principally of 

 black and white pigments, while the at- 

 mospheric gray is a vibratory effect re- 

 sulting from the movement of red, green, 

 and violet rays of light. The quality of 

 this gray alters from hour to hour as one 

 or the other of these chromatic rays pre- 

 dominates, and, manifestly, no single 

 pigmentary gray could accommodate 

 itself to these changes. Finally, the 

 character of a ship is indicated by her 

 body form and her upper works — details 

 that are emphasized by high lights and 

 strongly contrasting shadows. 



The submarine in the barred zones 

 seeks to close in upon its quarry during 



the dusk of early morning, or the close of 

 day or after nightfall, especially if the 

 moon helps to make the enemy craft 

 discernible. The camoufleur therefore 

 tries to reduce the visibility of vessels 

 during the periods of dim or half light, 

 and, curiously enough, the more scien- 

 tific of these men employ really vivid 

 coloring for the purpose. They paint 

 their ships with apparently meaningless 

 splotches of strong pink, blue, and green. 

 The patches become prominent agreeably 

 to the predominating light ray at the 

 time, and serve to obliterate those famil- 

 iar details or forms for which the observer 

 looks. Not only that, but normally 

 shaded areas are purposely painted light, 

 and the visual effect is flat and confusing. 

 There is dazzle and loss of definition in 

 fairly strong light, and, during periods of 

 twilight, atmospheric vibration induces a 

 gray tone that is so nearly akin to the sea 

 background that craft painted in this 

 marked fashion actually become invisible 

 at a mile ! 



Upon the field of a periscope there are 

 a number of horizontal lines as well as 

 vertical ones. The horizontal lines are 

 spaced to represent a prescribed height at 

 distances say of 1,000, 2,000, or 3.000 

 yards, while the vertical lines are spaced 

 to indicate definite intervals at those 

 different distances so as to determine the 

 speed of a vessel passing across them. 

 The U-boat commander, in order to 

 launch his torpedo with a fair chance of 

 hitting his target, must know how far off 

 the enemy ship is, whether her course is 

 bringing her closer or taking her away, 

 and approximately how fast she is moving. 

 With these factors fairly gaged, the tor- 

 pedo is pointed far enough ahead of the 

 target to allow for its time of flight and 

 the advance of the enemy craft. 



The commander of the submarine must 

 also be able to measure the height of his 

 quarry from her true waterline to the top 

 of her smokestack, which is a reasonably 



all 



