33 C.F.R. § 155.790
(a) A self-propelled vessel with a capacity of 250 or more barrels of oil or hazardous material that is conducting transfer operations between sunset and sunrise must have deck lighting that adequately illuminates—
(b) Where the illumination is apparently inadequate the OCMI or COTP may require verification by instrument of the levels of illumination. On a horizontal plane 3 feet above the deck the illumination must measure at least:
[CGD 75-124, 45 FR 7175, Jan. 31, 1980, as amended by CGD 86-034, 55 FR 36255, Sept. 4, 1990]