2026 China International Law of the Sea Moot Court Competition (2026 CHINA ILOSMCC)

The international law of the sea evolved from centuries of customary practice, beginning with Hugo Grotius's 1609 doctrine of mare liberum and competing claims to mare clausum, into a codified body of treaty law in the twentieth century. The first three UN Conferences on the Law of the Sea (1958, 1960, 1982) progressively narrowed disagreement over territorial sea breadth, fisheries jurisdiction, continental shelf rights, and the status of the deep seabed, culminating in the 1982 United Nations Convention on the Law of the Sea (UNCLOS). Alongside UNCLOS, customary international law, decisions of the International Court of Justice, awards of the International Tribunal for the Law of the Sea (ITLOS), and Annex VII arbitral tribunals continue to shape state practice. Contemporary disputes have made the law of the sea one of the most litigated areas of public international law. Cases such as the 2016 South China Sea Arbitration (Philippines v. China), the ITLOS Bangladesh/Myanmar and Ghana/Côte d'Ivoire maritime delimitations, the M/V Saiga and Arctic Sunrise prompt-release proceedings, and the 2024 ITLOS Advisory Opinion on climate change and the marine environment have tested doctrines on historic rights, archipelagic baselines, the status of low-tide elevations and rocks under Article 121(3), and states' due diligence obligations. Parallel negotiations on the 2023 Agreement on Marine Biodiversity of Areas Beyond National Jurisdiction (BBNJ) and renewed friction in the Arctic, Eastern Mediterranean, and South China Sea keep the field in active development. For moot purposes, the central tensions lie between coastal state sovereignty and the freedoms of navigation and overflight, between flag-state and port-state jurisdiction, and between treaty interpretation under VCLT principles and evolving environmental and human rights norms. Tribunals continue to refine how UNCLOS interacts with general international law, including the use of force at sea, marine scientific research, and the protection of the marine environment.

Adopted in Montego Bay on 10 December 1982 and entering into force on 16 November 1994, UNCLOS is often described as the 'constitution for the oceans.' It emerged from nine years of negotiation at UNCLOS III, designed to replace the fragmented 1958 Geneva Conventions with a comprehensive framework covering the territorial sea (12 nm), contiguous zone (24 nm), exclusive economic zone (200 nm), continental shelf (including extended claims under Article 76), the high seas, the Area and its mineral resources as the common heritage of mankind, and the protection of the marine environment. The 1994 Implementation Agreement on Part XI resolved the impasse over deep seabed mining that had kept industrialized states out of the Convention, while the 1995 UN Fish Stocks Agreement and the 2023 BBNJ Agreement extended the regime to straddling stocks and biodiversity beyond national jurisdiction. UNCLOS established a robust institutional architecture: the International Tribunal for the Law of the Sea in Hamburg, the International Seabed Authority in Kingston, and the Commission on the Limits of the Continental Shelf in New York. Part XV provides for compulsory dispute settlement, subject to the Article 297 limitations and Article 298 optional exceptions, which states such as China, Russia, and France have invoked to exclude categories including maritime delimitation and military activities. Landmark proceedings—from the MOX Plant case to the Chagos Marine Protected Area arbitration, the Enrica Lexie incident, and the recent ITLOS Advisory Opinion on climate change obligations—have shown both the reach and the contested limits of UNCLOS adjudication. Today, 169 parties have joined the Convention, but key issues remain unresolved: the legal status of features in semi-enclosed seas, the interaction of UNCLOS with sovereign immunity and the use of force, the regulation of marine genetic resources, the legal treatment of sea-level rise and disappearing baselines, and the operationalization of the BBNJ Agreement. These questions form the backbone of contemporary law-of-the-sea moot problems.