In times of disaster, we cannot overlook the importance of a marine approach to large-scale and safe evacuations of the populace. At the time of the Great East Japan Earthquake roads and railroads were disrupted, making rescue operations by land extremely difficult. Based on that experience, in a disaster prone country like Japan we believe that a system of medical provision by boat is necessary. Taking the Mercy-class hospital ships of the US Navy as a good example of hospital ships in operation by countries around the world, there is a need for Japan to acquire hospital ships to prepare for a large-scale disaster that might come any day.