Japan retained seaplanes because its island geography and exposure to earthquakes make land infrastructure vulnerable. An earthquake can split a runway while the surrounding water remains a potential operating surface. Water operations have hazards of their own, including tidal waves, so this is an argument for retaining another means of access when land infrastructure fails. Seaplanes offer a way to reach island communities or positions when land-based aviation is constrained. That geographic need underlies the use of ShinMaywa aircraft for rescue and the proposed reinforcement role.
Chapter · 7:16-8:15
Why Japan retained seaplanes
Japan's geography and exposure to earthquakes make water-operating aircraft a hedge against damaged runways and disrupted island infrastructure.