[Code of Federal Regulations]

[Title 33, Volume 1]

[Revised as of July 1, 2005]

From the U.S. Government Printing Office via GPO Access

[CITE: 33CFR84.15]



[Page 215-216]

 

                TITLE 33--NAVIGATION AND NAVIGABLE WATERS

 

         CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY

 

PART 84_ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES

--Table of Contents

 

Sec. 84.15  Intensity of lights.



    (a) The minimum luminous intensity of lights shall be calculated by 

using the formula:



I=3.43x10\6\xTxD\2\xK-D



where I is luminous intensity in candelas under service conditions,

T is threshold factor 2x10-7 lux,

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 

Table 84.15(b):



[[Page 216]]







                             Table 84.15(b)

------------------------------------------------------------------------

                                                        Minimum luminous

                                                          intensity of

   Range of visibility (luminous range) of light in         light in

                   nautical miles D                       candelas for

                                                             K=0.8 I

------------------------------------------------------------------------

1.....................................................               0.9

2.....................................................               4.3

3.....................................................              12

4.....................................................              27

5.....................................................              52

6.....................................................              94

------------------------------------------------------------------------