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Electronic Code of Federal Regulations

e-CFR data is current as of December 11, 2019

Title 33Chapter ISubchapter EPart 84 → §84.14


Title 33: Navigation and Navigable Waters
PART 84—ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES


§84.14   Intensity of lights.

(a) The minimum luminous intensity of lights shall be calculated by using the formula:

I = 3.43 × 106 × T × D2 × K−D

Where:

I is luminous intensity in candelas under service conditions,

T is threshold factor 2 × 10−7lux,

D is range of visibility (luminous range) of the light in nautical miles,

K is atmospheric transmissivity. For prescribed lights the value of K shall be 0.8, corresponding to a meteorological visibility of approximately 13 nautical miles.

(b) A selection of figures derived from the formula is given in the following table (Table 84.14(b)):

Table 84.14(b)

Range of visibility
(luminous range) of light
in nautical miles D
Minimum luminous intensity of light in candelas for K = 0.8 I
10.9
24.3
312
427
552
694

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