The question concerning the legality of China’s nine dash line has been the subject of arbitration proceedings at the Permanent Court of Arbitration (PCA) at The Hague. The case, which was submitted to the PCA by the Philippines for adjudication, raised issues which went beyond the main question concerning the legal status of the dash line as a maritime boundary under UNCLOS provisions. These included, inter alia, complaints concerning China’s activities within the area enclosed by the nine dash line, the status of maritime features within the maritime enclosure and alleged environmental damage caused by Chinese dredging and infrastructure building activities within the contested area. On 12 July 2016 the PCA rendered its judgment on the merits of the case. The main objective of this paper is to critically assess the implications of the PCA’s decision for the region and for the international law of the sea.