The document discusses international law of the sea as defined by the UN Convention on the Law of the Sea (UNCLOS). UNCLOS establishes that a coastal state's continental shelf extends at least 200 nautical miles from its coastline. For areas beyond 200 nautical miles, UNCLOS created the Commission on the Limits of the Continental Shelf to make recommendations on establishing boundaries. Adjacent states must also agree to delimit boundaries through negotiation or dispute settlement procedures in UNCLOS. The document then provides examples of how China, Iceland, Canada, Denmark, Norway, and Russia have ratified or made claims regarding their continental shelves and boundaries under UNCLOS.