33 CFR §173.77

1. (a)Except as provided in paragraphs (b), (c), (d), and (e) of this section, a certificate of number is valid until the date of expiration prescribed by the issuing authority.
2. (b)A certificate of number issued by an issuing authority is invalid after the date upon which:
   1. (1)The vessel is documented or required to be documented under Part 67 of Title 46, Code of Federal Regulations;
   2. (2)The person whose name appears on the certificate of number as owner of the vessel transfer all of his or her ownership in the vessel; or
   3. (3)The vessel is destroyed or abandoned.
3. (c)A certificate of number issued by an issuing authority is invalid if:
   1. (1)The application for the certificate of number contains a false or fraudulent statement; or
   2. (2)The fees for the issuance of the certificate of number are not paid.
4. (d)A certificate of number is invalid 60 days after the day on which the vessel is no longer principally operated in the State where the certificate was issued.
5. (e)The certificate of number is invalid when the person whose name appears on the certificate involuntarily loses his or her interest in the numbered vessel by legal process.