China’s demands exceed the legal claims established by UNCLOS, even though that treaty was ratified by Beijing. The PRC claims are based in a map named ‘Map of Chinese Islands in the South China Sea,’ originally issued in 1947 and therefore pre-dating the existence of the PRC and based on supposed historical rights dating back to the quasi-legendary Xia dynasty (c. 2070-1600 BC) – the very first dynasty to emerge in ancient China (Baumert and Melchior 2014). The PRC claim based on this ancient inheritance is for the entire area enclosed by the lines to be considered Chinese territorial waters. This runs counter to the 12 nautical miles conferred by UNCLOS rules on overlapping EEZ claims, territorial seas, and areas adjacent to several other countries in the region. It is worth noting that China is not the only actor in the SCS that is a signatory to UNCLOS and whose claims exceed what that document establishes as legal.


Is it common to have territorial claims that exceeds by the limitations established by the UNCLOS (United Nations Convention on the Law of the Sea)?

China is a signatory yet its territorial claims exceed the limitations established by UNCLOS. I was wondering how common it was for a country to do that either it is a signatory of UNCLOS or not. In my knowledge, Taiwan also have the same territorial claims surprisingly enough, but I was wondering if any other country also have similar claims that doesn't respect UNCLOS.

  • 1
    The Chinese claim is usually referred to as the 'nine-dash line'. I don't know why your source doesn't call it that way.
    – quarague
    Aug 21, 2023 at 12:32
  • 1
    Of the 32 cases the International Tribunal for the Law of the Sea has taken on since its inception in 1996, four were sea border disputes.
    – ccprog
    Aug 21, 2023 at 13:06

3 Answers 3


I am unsure how common it is, but The Arctic Sea is definitely also a tug of war where UNCLOS is challenged.



The PRC claims are based in a map named ‘Map of Chinese Islands in the South China Sea,’ originally issued in 1947 and therefore pre-dating the existence of the PRC

My understanding is China's claims were originally based on historical possession not historical islands. Historical possessions of territorial water are not recognized by international law. Building of artificial islands allowed China to merge historical claims which are not recognized by UNCLOS with a new claim they tried to present as ones more in alignment with UNCLOS. After building 7 large islands inside or near other nations waters, China tried to claim UNCLOS territorial and exclusive economic zones around their new islands. UNCLOS found in July 2016, that china's claims were without merit. The reasoning is that the artificial "islands" do not have naturally occurring fresh water and thus cannot support life. Thus they aren't islands but rocks and rocks don't have territorial waters by existing laws.

Which has lead to a constant stream of Chinese claims of finding fresh water on their artificial islands.

Fresh Water Reservoir Found on one of Beijing's Artificial Islands

and photographs of how green they are.

Is it prevalent to have territorial claims that exceeds by the limitations established by UNCLOS?

I don't think it's prevalent. I do know the United States which did not sign the UNCLOSE treaty currently claims territorial waters near a Hawaiian island which UNCLOSE doesn't recognize. This water is not claimed by any other nation but it is outside of the range permitted by UNCLOSE.

  • This answer could be improved by covering the UNCLOS's more generous rules for archipelago nations, and China's claim to that status. Aug 24, 2023 at 16:41

China may be eyeing the Canadian EEZ between Moresby and Vancouver islands as a reference to what they may claim:

Canadian EEZ

Unless I'm misreading the map, that's 210 kilometers of Canadian ocean EEZ between these two landmasses. In other cases, no such EEZ is claimed, such as St. Lawrence island does not claim continuous EEZ all the way to the coast of Alaska despite being closer.

Perhaps China thinks that by claiming the chain of their islands is a historic nautical border of China, they may get to have a similarly large EEZ eventually. Worked for Canada.

  • Moresby and Vancouver islands both have water. Thus like Hawaii, St Croix, and Puerto Rico they are entitled to 200 mile Exclusive Economic Zones and when you add Canada which also has natural recurring water it's EEZ gives Canada those rights. China's problem is in creating their artificial islands within the EEZ of other nations they dredged up coral reefs. No naturally occuring water. so they're not Islands just rocks stacked on top of each other. Thus no EEZ and never will be.
    – user47010
    Aug 28, 2023 at 20:42

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