Vertical surfaces from boot-topping to top of
superstructure masses including masts, A pattern consisting of Thayer
Blue 5-B and White
The special feature of this system is its
changeable character. At low level of illumination a blue paint will
appear relatively lighter and a red paint will appear relatively darker than
these two paints appear in daylight. This visual change, known as
the Purkinje effect, is utilized in the Thayer System. The pure light
blue which is employed has been selected because it will appear practically
like white paint at low levels of illumination. The ship will
therefore appear like a white ship on moonless nights or during twilight
when white or very light ships are best for reduced visibility. During
daylight hours or under bright moonlight the pattern will appear and will
produce some deception in the estimation of the target angle. A darker
blue would produce more deception but can not be used because it will not
appear white at night. The purity of the color is an important factor
in the Purkinje effect, and even a slight admixture of black in the paint
will reduce its effectiveness at night.
The camouflage painting need not be exact or carried
into corners. Small gear, wires, rigging, and areas permanently in
shadow, as under boats, etc., need not be painted with the camouflage
colors. There is no objection to exact or careful painting which may be
desired for the sake of good appearance at close range.
All bright or shiny objects, no matter how
insignificant, shall be painted, covered, or removed.
Glass windows shall be covered or removed, especially
during the day in sunny weather, and at night when anticipating searchlight
discovery. Insofar as conditions permit, similar precautions shall be
taken on airport lenses.