Certificate of Registry

A certificate of registry is the document evidencing a ship’s nationality and ownership, issued by the flag state’s registrar on entry in the national register. It records the name, port of registry, official number, tonnage, build details, and registered owner, and is the legal proof the ship is entitled to fly that flag. UNCLOS Article 91 requires a genuine link between state and ship and the state to issue documents to vessels it grants its nationality; Article 92 ties the ship to one flag. It must be carried on board and produced to authorities.