Code of Federal Regulations Title 33. Navigation and Navigable Waters § 33.107.210 Applicability

(1) Vessels of the United States less than 100 meters (328 feet) in length (and all associated auxiliary vessels) and the owners, agents, masters, officers, persons in charge, and members of the crew of such vessels, that depart U.S. territorial waters and thereafter enter Cuban territorial waters, regardless of whether such entry is made after an intervening entry into, passage through, or departure from any other foreign territory or territorial waters;

(2) Vessels of the United States less than 100 meters (328 feet) in length (and all associated auxiliary vessels) and the owners, agents, masters, officers, persons in charge, and members of the crew of such vessels that are located at or get underway from a berth, pier, mooring, or anchorage in U.S. territorial waters, or depart U.S. territorial waters with the intent to enter Cuban territorial waters;  and

(3) Any person who knowingly fails to comply with this subpart or order given under this subpart, or knowingly obstructs or interferes with the exercise of any power conferred by this subpart.