Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS) sets out the legal regime governing the novel ‘continental shelf beyond 200 nautical miles’ or ‘the outer continental shelf’. As Article 76 contains a complex interface between law and science, its interpretation and application raises intricate issues, with which no international court or tribunal had dealt with substantively before 2012. The UNCLOS dispute settlement bodies were the first international tribunals to provide answers to long-standing questions surrounding the meaning and application of several important, but ambiguous or controversial, legal terms employed under Article 76. As such, the decisions rendered by the UNCLOS tribunals have been seen as playing an important role in elucidating the legal regime of the outer continental shelf. This article queries this assessment by critically examining whether and to what extent the relevant pronouncements made by UNCLOS tribunals have contributed to clarifying and developing the law governing the outer continental shelf regime under UNCLOS.

In the South China Sea Arbitration initiated by the Philippines against China, the Chinese (Taiwan) Society of International Law (CSIL) submitted an amicus curiae brief to the Annex VII arbitral tribunal established in accordance with United Nations Convention on the Law of the Sea (UNCLOS). This article first analyzes the definition and legal nature of amicus curiae status, then introduces cases involving amicus curiae in the International Court of Justice (ICJ) and UNCLOS dispute settlement mechanisms. By analyzing relevant statutes and rules of procedure, this article assesses the acceptance of amicus curiae submissions by international courts or tribunals, in different dispute settlement mechanisms. Finally, the article describes the significance of the amicus curiae brief submitted by CSIL to the arbitral tribunal, concluding that the South China Sea Arbitral Tribunal did take the amicus curiae submission into account, but exercised caution in its consideration.