Earlier this month, China quietly turned a swathe of the Gulf of Tonkin into an extension of Chinese internal waters, simply by declaring a new baseline across the gulf’s northeastern end. If Beijing’s unilateral declaration stands, a crescent-shaped area extending up to 50 nautical miles from the Chinese coast will be fully subject to China’s domestic laws, Maritime Executive reports.
Per UNCLOS the UN Convention on the Law of the Sea, a normal baseline is the edge of the shoreline, and it is the starting point for measuring a nation’s territorial sea. China has moved that starting line far offshore using UNCLOS’ straight-baseline clause, which was designed to simplify maritime demarcation for complex coastlines – for example, western Norway, which is a maze of islands and fjords. Using straight baselines to “smooth” the legal shape of a rugged coastline, a nation with a fringe of islands or inlets can delineate rational maritime boundaries.
In keeping with this purpose, UNCLOS requires that straight baselines must follow the general direction of the coast, and any sea area on the landward side of the baseline must be closely linked to the nation’s jurisdiction.
“It’s very clear from the maps . . . that China’s new baselines depart considerably from the general direction of the coast,” Chatham House associate fellow Bill Hayton told Newsweek.
