The terms international waters or trans-boundary 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.

Oceans, seas, and waters outside of national jurisdiction are also referred to as the high seas or, in Latin, mare liberum.

Ships sailing the high seas are generally under the jurisdiction of the flag state; however, when a ship is involved in certain criminal acts, such as piracy, any nation can exercise jurisdiction under the doctrine of hostis humani generis.

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 military and commercial shipping.

• Several conventions have opened the Bosporus and Dardanelles to shipping. The latest, the Montreux Convention Regarding the Regime of the Turkish Straits maintains the straits' status as an international waterway.

Other international treaties have opened up rivers, which are not traditionally international waterways.

• The Danube River has been internationalized so that landlocked Austria, Hungary and former Czechoslovakia (now only Slovakia) have access to the Danube, and southern Germany (Germany itself is not landlocked, having access to both the North Sea and Baltic Sea) could have secure access to the Black Sea.

Disputes over International waters

For more information see Territorial claims in the Arctic and Northwest Passage.

Current unresolved disputes over whether particular waters are "International waters" include:

• The Arctic Ocean: While Canada, Denmark, Russia and Norway all regard parts of the Arctic seas as "national waters" or "internal waters", the United States and most European Union countries officially regard the whole region as international waters.

International waters agreements

Global agreements

• (freshwater only).

• The profiles agreements regarding the , and .

• 1972 London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter ()

• 1973 London International Convention for the Prevention of Pollution from Ships, 1973 MARPOL

• 1984 United Nations Convention on Law of the Sea (, United Nations - especially parts XII-XIV.)

• 1997 United Nations Convention on the Law of Non-Navigational Uses of International Watercourses () - not ratified

• Transboundary Groundwater Treaty, - proposed, but not signed''

• Other global conventions and treaties with implications for International Waters:

• * 1971 Ramsar Convention on Wetlands ()

• * 1992 Convention on Biological Diversity especially Articles 12-13, as related to transboundary aquatic ecosystems)

Regional agreements

At least ten conventions are included within the of UNEP, including:

• the Atlantic Coast of West and Central Africa (

• the North-East Pacific (Antigua Convention);

• the Mediterranean (Barcelona Convention);

• the wider Caribbean (Cartagena Convention);

• the South-East Pacific (, 1986);

• the South Pacific (Nouméa Convention);

• the East African seaboard (, 1985);

• the Kuwait region (Kuwait Convention);

• the Red Sea and the Gulf of Aden (Jeddah Convention).

Addressing regional freshwater issues is the 1992 Helsinki (UNECE/Helsinki Water Convention)

Water body-specific agreements

• Baltic Sea (Helsinki , 1992)

• Black Sea (,1992), see also the ;

• Caspian Sea (, 2003)

• Lake Tanganyika (, 2003)

International waters institutions

Freshwater institutions

• The UNESCO International Hydrological Programme ()

• The International Joint Commission between Canada and USA ()

• The International Network of Basin Organizations ()

• The project

• The (US Section) between Mexico and USA

• The International Water Management Institute ()

• The World Conservation Union Water and Nature Initiative ()

Marine institutions

• The International Maritime Organization ()

• The International Seabed Authority

• The International Whaling Commission

• The UNEP

• The UNESCO Intergovernmental Oceanographic Commission ()

• The

• The World Conservation Union Global Marine Program ()

See also

• Freedom of the seas

• Baseline

• Exclusive economic zone

• Continental shelf

• Territorial waters

• Internal waters

• Birth aboard aircraft and ships

• Seasteading

• Hugo Grotius