The flag State Administration must ensure that ships of less than 400 GT are equipped, as far as practicable, to retain on board oil or oily mixtures or discharge them in accordance with the following requirements:
(1) the ship is proceeding en route; (2) the ship has in operation equipment of a design approved by the flag State Administration that ensures that the oil content of the effluent without dilution does not exceed 15 ppm; (3) the oily mixture does not originate from cargo pump room bilges on oil tankers; and (4) the oily mixture, in case of oil tankers, is not mixed with oil cargo residues (MARPOL Annex I, reg. 14.4)
