1. Regulations
  2. title 33
  3. chapter I
  4. part 84
  5. § 84.14

View all text of Part 84 [§ 84.01 - § 84.20]

§ 84.14 - Intensity of lights.

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

I = 3.43 × 10 6 × T × D 2 × 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

AUTHORITY: Sec. 303, Pub. L. 108-293, 118 Stat. 1042 (33 U.S.C. 2071); Department of Homeland Security Delegation No. 0170.1.

SOURCE: 79 FR 37921, July 2, 2014, unless otherwise noted.

CITE AS: 33 CFR 84.14