(a) If a port director receives a request from a Coast Guard officer to refuse or revoke the clearance or permit to proceed of a vessel because the vessel, its owner, operator, or person in charge, is liable for a fine or civil penalty, or reasonable cause exists to believe that they may be subject to a fine or civil penalty under the provisions of 33 U.S.C. 1908 for violating the Protocol of 1978 Relating to the International Convention for the Prevention of Pollution from Ships, 1973 (MARPOL Protocol), the Act to Prevent Pollution from Ships, 1980 (33 U.S.C. 1901-1911), or regulations issued thereunder, such clearance or a permit to proceed shall be refused or revoked. Clearance or a permit to proceed may be granted when the port director is informed that a bond or other security satisfactory to the Coast Guard has been filed.

(b) If a port director receives a notification from a Coast Guard officer that an order has been issued to detain a vessel required to have an International Oil Pollution Prevention (IOPP) Certificate which does not have a valid certificate on board, or whose condition or whose equipment's condition does not substantially agree with the particulars of the certificate on board, or which presents an unreasonable threat of harm to the marine environment, the port director shall refuse or revoke the clearance or permit to proceed of the vessel if requested to do so by a Coast Guard officer. The port director shall not grant clearance or issue a permit to proceed to the vessel until notified by a Coast Guard officer that detention of the vessel is no longer required.

(c) If a port director receives a notification from a Coast Guard officer to detain a vessel operated under the authority of a country not a party to the MARPOL Protocol which does not have a valid certificate on board showing that the vessel has been surveyed in accordance with and complies with the requirements of the MARPOL Protocol, or whose condition or whose equipment's condition does not substantially agree with the particulars of the certificate on board, or which presents an unreasonable threat of harm to the marine environment, the port director shall refuse or revoke the clearance or permit to proceed of the vessel if requested to do so by a Coast Guard officer. The port director shall not grant clearance or issue a permit to proceed to the vessel until notified by a Coast Guard officer that detention of the vessel is no longer required.