The terms international waters or transboundary waters apply where any of the following types of bodies of water (or their
drainage basins) transcend international boundaries: oceans,
large marine ecosystems, enclosed or semi-enclosed regional seas and
estuaries, rivers, lakes,
groundwater systems (
aquifers), and
wetlands.[1]
"International waters" is not a defined term in international law. It is an informal term, which sometimes refers to waters beyond the "territorial sea" of any country.[2] In other words, "international waters" is sometimes used as an informal synonym for the more formal term "high seas", which under the doctrine of mare liberum (
Latin for "freedom of the seas"), do not belong to any state's jurisdiction. As such, states have the right to fishing, navigation, overflight, laying cables and pipelines, as well as scientific research.
The
Convention on the High Seas, signed in 1958, which has 63 signatories, defined "high seas" to mean "all parts of the sea that are not included in the
territorial sea or in the
internal waters of a State" and where "no State may validly purport to
subject any part of them to its sovereignty."[3] The Convention on the High Seas was used as a foundation for the
United Nations Convention on the Law of the Sea (UNCLOS), signed in 1982, which recognized
exclusive economic zones extending 200 nautical miles (230 mi; 370 km) from the baseline, where coastal states have sovereign rights to the water column and sea floor as well as the natural resources found there.[4]
The high seas make up 50% of the surface area of the planet and cover over two-thirds of the ocean.[5]
UNCLOS also contains, in its part XII, special provisions for the protection of the marine environment, which, in certain cases, allow
port States to exercise extraterritorial jurisdiction over foreign ships on the high seas if they violate international environmental rules (adopted by the
IMO), such as the
MARPOL Convention.[8]
International waterways
Several international treaties have established
freedom of navigation on semi-enclosed seas.
The
Copenhagen Convention of 1857 opened access to the
Baltic by abolishing the
Sound Dues and making the
Danish Straits an international waterway free to all commercial shipping. Separately, the Royal Ordinance of 1999 regulates the access of foreign warships to Danish waters.[9][10][11]
Current unresolved disputes over whether particular waters are "International waters" include:
Arctic Ocean: While Canada, Denmark, Russia and Norway all regard parts of the Arctic seas as national waters or internal waters, most
European Union countries and the United States officially regard the whole region as international waters. The
Northwest Passage through the
Arctic Archipelago is one of the more prominent examples, with Canada claiming it as
internal waters, while the United States and the European Union considers it an international strait.[12]
International Freshwater Treaties Database (freshwater only).[13]
The Yearbook of International Cooperation on Environment and Development profiles agreements regarding the Marine Environment, Marine Living Resources and Freshwater Resources.[14]
Addressing regional freshwater issues is the 1992
Helsinki Convention on the Protection and Use of Transboundary Watercourses and International Lakes (
UNECE/Helsinki Water Convention)[25]
When an underground body of water transcends international boundaries, the term transboundary aquifer applies.
UNESCO has recognized the issue in several publications like Transboundary Aquifers, Challenges and the way forward.[30]
Another term referring to underground international waters is Transboundariness. It is a concept, a measure and an approach first introduced in 2017.[31] The relevance of this approach is that the physical features of the aquifers become just additional variables among the broad spectrum of considerations of the transboundary nature of an aquifer:
social (population);
economic (groundwater productivity);
political (as transboundary);
available research or data;
water quality and quantity;
other issues governing the agenda (security, trade, immigration and so on).
The discussion changes from the traditional question of "is the aquifer transboundary?" to "how transboundary is the aquifer?".
The socio-economic and political contexts effectively overwhelm the aquifer's physical features adding its corresponding geostrategic value (its transboundariness) [32]
The criteria proposed by this approach attempt to encapsulate and measure all potential variables that play a role in defining the transboundary nature of an aquifer and its multidimensional boundaries.[33]
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abThe term "international waters" technically includes the "Contiguous Zone" and "Exclusive Economic Zone," although the chart only uses this term where no national jurisdiction or special rights apply.