Natural prolongation principle

The natural prolongation principle or principle of natural prolongation is a legal concept introduced in maritime claims submitted to the United Nations.

The phrase denotes a concept of political geography and international law — that a nation's maritime boundaries should reflect the 'natural prolongation' of where its land territory reaches the coast. Oceanographic descriptions of the land mass under coastal waters became conflated and confused with criteria which are deemed relevant in border delimitation. This concept was developed in the process of settling disputes where the borders of adjacent nations were located on a contiguous continental shelf.