No master or owner of any vessel registered or licensed in the Republic shall anywhere, and no master of any vessel not registered or licensed in the Republic shall in the Republic or the territorial waters thereof, permit persons to be on board or on or in any part of the vessel in excess of the number permitted by the vessel’s safety convention certificate, local safety certificate, memorandum referred to in section one hundred and ninety-six or certificate referred to in subsection (4) or (5) of section two hundred and three: Provided that the Authority may, for the purpose of enabling persons to be moved from any place in consequence of a threat to their lives, authorize more persons to be carried on board a ship than are permitted by the said certificate or memorandum; and the carriage of persons in accordance with such authority shall not constitute a contravention of the provisions of this section.