33 CFR § 157.01 - Applicability.
(1) Documented under the laws of the United States (a U.S. vessel); or
(2) Any other vessel that enters or operates in the navigable waters of the United States, or that operates, conducts ligtering under 46 U.S.C. 3715, or receives cargo from or transfers cargo to a deepwater port under 33 U.S.C. 1501 et seq., in the United States Exclusive Economic Zone, as defined in 33 U.S.C. 2701(8).