46 CFR §67.171

1. (a)A Certificate of Documentation together with any endorsement(s) thereon is invalid, except as provided in § 67.161, and the vessel is subject to deletion from the roll of actively documented vessels when:
   1. (1)The vessel is placed under foreign flag;
   2. (2)The vessel is sold or transferred in whole or in part to a person who is not a citizen of the United States within the meaning of subpart C of this part;
   3. (3)Any owner of the vessel ceases to be a citizen of the United States within the meaning of subpart C of this part;
   4. (4)The owner no longer elects to document the vessel;
   5. (5)The vessel no longer measures at least five net tons;
   6. (6)The vessel ceases to be capable of transportation by water;
   7. (7)The owner fails to exchange the Certificate as required by § 67.167;
   8. (8)The owner fails to maintain the markings required by subpart I of this part;
   9. (9)The endorsements on the Certificate are revoked because the vessel owner is the subject of an outstanding civil penalty assessed by the Coast Guard; or
   10. (10)The owner fails to:
       1. (i)Renew the endorsement(s) as required by § 67.163; or
       2. (ii)Comply with the provisions of § 67.165.
2. (b)Where a cause for deletion arises for any reason under paragraphs (a)(1) through (6) of this section, the owner must send to the National Vessel Documentation Center a statement setting forth the reason(s) deletion is required.
3. (c)When a Certificate of Documentation is required to be deleted because the vessel has been placed under foreign flag or has been sold or transferred in whole or in part to a non-citizen of the United States, the owner of that vessel must comply with the requirements of paragraph (b) of this section, and file:
   1. (1)Evidence of the sale or transfer, if any; and
   2. (2)Evidence that the Maritime Administration has consented to the sale or transfer, except for vessels identified in § 67.11(b) and vessels for which the Maritime Administration has granted approval for unrestricted sale or transfer pursuant to regulations set forth in 46 CFR part 221.
4. (d)A certificate evidencing deletion from U.S. documentation will be issued upon request of the vessel owner to the National Vessel Documentation Center upon compliance with the applicable requirements of this subpart.