33 CFR § 104.205 - Master.
(a) Nothing in this part is intended to permit the Master to be constrained by the Company, the vessel owner or operator, or any other person, from taking or executing any decision which, in the professional judgment of the Master, is necessary to maintain the safety and security of the vessel. This includes denial of access to persons—except those identified as duly authorized by the cognizant government authority—or their effects, and refusal to load cargo, including containers or other closed cargo transport units.
(b) If, in the professional judgment of the Master, a conflict between any safety and security requirements applicable to the vessel arises during its operations, the Master may give precedence to measures intended to maintain the safety of the vessel, and take such temporary security measures as seem best under all circumstances. In such cases:
(1) The Master must, as soon as practicable, inform the nearest COTP. If the vessel is on a foreign voyage, the Master must promptly inform the Coast Guard via the NRC at 1–800–424–8802, direct telephone at 202–267–2675; Fax: 202–267–1322, TDD at 202–267–4477, or E-mail at HQS-DG-lst-NRCINFO@uscg.mil and if subject to the jurisdiction of a foreign government, the relevant maritime authority of that foreign government;
(2) The temporary security measures must, to the highest possible degree, be commensurate with the prevailing Maritime Security (MARSEC) Level; and
(3) The owner or operator must ensure that such conflicts are resolved to the satisfaction of the cognizant COTP, or for vessels on international voyages, the Commandant (CG-5P), and that the possibility of recurrence is minimized.