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Official Number


BoatWiki - Definitions


An official number can be defined in boating terms as the unique six or seven digit identifier assigned by the U.S. Coast Guard upon initial documentation of a vessel. Vessel documentation may or may not apply to any vessel over approximately 24 feet in length. The official number is also knows as an O/N, vessel documentation number, or USCG documentation number.


When a vessel is first documented it is assigned a unique number that must be affixed inside the hull or an integral part of the hull in a visible place. Such marking is preceded by the designation O.N. which is an abbreviation for "official number". The Coast Guard then views it as the primary identifier along with the hull identification number. Documentation numbers are also known as document or official  numbers.


Documentation numbers consist of seven digits for newer registrations and six digits for older vessels. All references with the National Vessel documentation center can be made by either the documentation or hull number. The same can be said when conducting record searches on the internet.


Research should be conducted on a known documentation number regardless of whether the vessel is still actively documented. Such records are maintained indefinitely by the Coast Guard and can provide vital information.

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4/22/2022 - Page initiated by Team BoatWiki.


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