This bill directs the Coast Guard to prescribe regulations to require operators of amphibious passenger vessels to provide reserve buoyancy for such vessels through passive means, including watertight compartmentalization, built-in flotation, or other means, to ensure that such vessels remain afloat and upright in the event of flooding, including when carrying a full complement of passengers and crew. The bill sets forth interim requirements for vessels that are not in compliance with the regulations. The bill prohibits vessels whose configuration or operation does not comply with the regulations or interim requirements from operating on U.S. waterways.