[xnull2guest]

UNCLOS has no authority on sovereignty disputes, right?

http://www.un.org/Depts/los/convention_agreements/texts/uncl...

[JumpCrisscross]

See my answer here [1]. You are mis-interpreting Article 298. Its potential effect on the Tribunal's jurisdiction was argued by China and struck down by the Tribunal [2].

[1] https://news.ycombinator.com/item?id=13203195

[2] http://www.pcacases.com/web/sendAttach/1506 §§ 397 - 412