Maritime sovereignty · 200 nautical miles
An exclusive economic zone extends up to 200 nautical miles — 370 km — from the coast. The state holds exclusive exploitation rights there: fishing, hydrocarbons, offshore wind, polymetallic nodules. It is not sovereign there as it is on land.
UNCLOS, Montego Bay, 1982. Areas include overseas territories, which transforms the ranking: an EEZ is measured from every island, inhabited or not, never from the mainland alone.
The map rewards not land area but the number and dispersion of islands. An isolated atoll of a few square kilometres generates over 400,000 km² of maritime space.
France holds the world's largest EEZ, ahead of the United States, thanks to French Polynesia and New Caledonia — without its overseas territories it would fall out of the top 30. In 2016 the Permanent Court of Arbitration found China's South China Sea claims to have no legal basis; Beijing rejected the ruling.