US Code states that any vessel that does not operate on America’s navigable waters or EEZ (Exclusive Economic Zone) fisheries is exempt from a requirement to be documented.
Vessels measuring less than five net tons are excluded from documentation as well, according to Cornell law.
Non-self-propelled vessels which are qualified to engage in coastwise trade are exempt from the requirement to be documented with a coastwise endorsement even when they are in engaged in coastwise trade provided they are either within a harbor, on the internal.