46 USC 3314 - Expiration of certificate of inspection

(a) If the certificate of inspection of a vessel expires when the vessel is on a foreign voyage, the vessel may complete the voyage to a port of the United States within 30 days of the expiration of the certificate without incurring the penalties for operating without a certificate of inspection.
(b) If the certificate of inspection would expire within 15 days of sailing on a foreign voyage from a United States port, the vessel shall secure a new certificate of inspection before sailing, unless the voyage is scheduled to be completed prior to the expiration date of the certificate. If a voyage scheduled to be completed in that time is not so completed, the applicable penalties may be enforced unless the failure to meet the schedule was beyond the control of the owner, charterer, managing operator, agent, master, or individual in charge of the vessel.
(c) When the certificate of inspection of a foreign vessel carrying passengers, operated on a regularly established line, expires at sea after leaving the country to which it belongs or when the vessel is in the United States, the Secretary may permit the vessel to sail on its regular route without further inspection than would have been required had the certificate not expired. This permission applies only when the vessel will be regularly inspected and issued a certificate before the vessels next return to the United States.