1. Requirements for amphibious passenger vessels to remain afloat and upright in the event of flooding (a) Reserve buoyancy for amphibious passenger vessels through passive means (1) Regulations required Not later than 180 days after the date of the enactment of this Act, the Commandant of the Coast Guard shall prescribe in regulations requirements that operators of amphibious passenger vessels provide reserve buoyancy for such vessels through passive means, including watertight compartmentalization, built-in flotation, or such other means as the Commandant shall specify in the regulations, in order to ensure that such vessels remain afloat and upright in the event of flooding, including when carrying a full complement of passengers and crew. (2) Deadline for compliance The regulations required by paragraph (1) shall require compliance with the requirements in the regulations by operators of amphibious passenger vessels by such date, not later than 24 months after the date of the enactment of this Act, as the Commandant shall specify in the regulations. (b) Interim requirements Commencing as of the date the regulations required by subsection (a) are prescribed, the Commandant of the Coast Guard shall require that operators of amphibious passenger vessels that are not in compliance with the requirements in the regulations do the following: (1) Remove the canopies of such vessels for waterborne operations, or install in such vehicles a Coast Guard-approved canopy that does not restrict either horizontal or vertical escape by passengers in the event of flooding or sinking. (2) If the canopy is removed from any such vessel pursuant to paragraph (1), require that all passengers don a Coast Guard type-approved personal flotation device before the onset of waterborne operations of such vessel. (3) Reengineer such vessels to permanently close all unnecessary access plugs and to reduce all through-hull penetrations to the minimum number and size necessary for operation. (4) Install in such vessels independently powered