The most basic USCG requirements for documentation are: a vessel that measures five net tons or more and is wholly owned by an American citizen.
According to the Code of Federal Regulations, “this includes, but is not limited to, vessels used exclusively for recreational purposes and vessels used in foreign trade.”
A vessel that is 26 feet or longer is likely to measure five net tons.
Vessels that are engaged in fishery or coastwise trade activities on the navigable waters of the United States or the Exclusive Economic Zone must be documented. Vessel owners who wish to obtain a Preferred Ship’s Mortgage will most likely have to document their vessels as well.