"International law is likely to be invoked again over island-expansion elsewhere in Asia. Japan argues that its remote southern outcrop of Okinotorishima is an island, which, under UNCLOS, would entitle it to “territorial waters” within a 12-nautical-mile (22km) radius, and a 200-mile “Exclusive Economic Zone” (EEZ). China argues it is not an island at all but a rock, incapable of sustaining human habitation, and so, under UNCLOS, commands only territorial waters, not an EEZ. The argument is complicated by Japan’s efforts to make the island grow by using star sand, the shells of a tiny single-celled organism found near coral reefs in Japan’s south. Scientists have learned how to grow this artificially, and the government hopes thereby to strengthen Okinotorishima’s claim to island status. Even if they managed this scientific feat, it might not pass legal muster with UNCLOS. Rocks and islands must be “naturally formed”. So can rocks be transformed into islands through man-made sand?
The law is explicit that ground that is submerged at high tide—known as “low-tide elevations”—commands neither territorial waters nor EEZs, and cannot be built up into “rocks”. This is an important issue in the complex overlapping territorial disputes in the South China Sea, where China is reclaiming land in contested areas. In a submission to an UNCLOS tribunal, the Philippines has asked that three features China is developing be categorised as “low-tide elevations” and three as “rocks”."
https://www.economist.com/news/asia/21645221-asias-mania-reclaiming-land-sea-spawns-mounting-problems-such-quantities-sand
The law is explicit that ground that is submerged at high tide—known as “low-tide elevations”—commands neither territorial waters nor EEZs, and cannot be built up into “rocks”. This is an important issue in the complex overlapping territorial disputes in the South China Sea, where China is reclaiming land in contested areas. In a submission to an UNCLOS tribunal, the Philippines has asked that three features China is developing be categorised as “low-tide elevations” and three as “rocks”."
https://www.economist.com/news/asia/21645221-asias-mania-reclaiming-land-sea-spawns-mounting-problems-such-quantities-sand