What happens to the boundaries of the marine estate when the sea advances or retreats?
If the process of change is natural, and happens imperceptibly from day to day, then ownership changes accordingly. Therefore, if land used to be tidal (e.g. foreshore or riverbed), it becomes the property of the adjacent landowner. Conversely if land erodes and naturally converts to tidal, then it becomes the property of the tidal landowner. Often this can be The Crown Estate. If the change is sudden and immediately visible, e.g. the breaching of flood defences in a storm, then the ownership remains as it was unless alternative agreements are made. The same is the case where changes occur as a result of man’s actions, e.g. reclamation or digging out basins.
