This paper provides an assessment of the Tribunal’s Award on the merits relating to the Philippines’ Submissions No. 1 and 2. First, it argues that the Convention is not the sole legal source of maritime rights. Second, the Tribunal erroneously infers from Article 311 that the Convention prevails over customary international law. Meanwhile, Article 293 does not terminate rules of general international law that are incompatible with the Convention. Third, the Tribunal, by deciding that historic rights under general international law have been superseded by the regimes of exclusive economic zone and continental shelf established under the Convention, fails to draw a distinction between the two separate legal regimes, namely the Convention and general international law. Fourth, as one of the “matters not regulated by the Convention”, historic rights should be governed by, and have been well established in, general international law.