46 C.F.R. § 67.173
A Certificate of Documentation issued to a vessel together with any endorsement(s) thereon is invalid, except as provided in § 67.161 , and subject to cancellation upon a determination by the Director, National Vessel Documentation Center that the issuance of the Certificate was improper for any reason. When a Certificate is subject to cancellation, the owner of the vessel upon being notified of such requirement must send or deliver the Certificate to a documentation officer at the National Vessel Documentation Center. The vessel owner may submit an application for exchange in accordance with subpart K of this part to correct the error giving rise to cancellation. If the vessel for which the Certificate was cancelled was previously documented, it remains documented under the previous Certificate of Documentation, unless deleted under the provisions of § 67.171 .
46 C.F.R. §67.173
Certificates of Documentation which have been canceled are retained at the National Vessel Documentation Center.