This book explores interfaces between land and sea and their geostrategic, ecological, urban, productive, indigenous, legal, historical, and artistic dimensions. The oceans, comprising two-thirds of the earth's surface, were initially utilised mainly for transportation and fishing. Today they serve diverse purposes such as supplying energy, freshwater, mineral resources, supporting leisure activities, and providing habitat. Additionally, the UN set up the first international agreement establishing Marine Protection Areas for a third of the sea to mitigate the growing use and exploitation. The more interest in oceans' territories increases, the more the question arises about the beneficial evolution of their physical and legal boundaries. What innovative amphibious concepts can be developed for the edge of the sea? The book pushes the boundaries of current knowledge to provide a deeper insight into the upcoming challenges and opportunities, makingit easier to apply the best strategies for a healthy future for both the ocean and humanity.