Except as allowed in § 157.158 , the master of a foreign tank vessel having a COW system under § 157.10(e) , § 157.10a(a)(2) , or § 157.10c(b)(2) that has the Crude Oil Washing Operations and Equipment Manual approved under § 157.112 and is operating in the navigable waters of the United States or transferring cargo at a port or place subject to the jurisdiction of the United States and the master of a U.S. tank vessel having a COW system under § 157.10(e) , § 157.10a(a)(2) , or § 157.10c(b)(2) shall ensure that during each COW operation-
33 C.F.R. §157.156