International waters

The terms international waters or trans-boundary waters apply where any of the following types of bodies of water
Body of water
A body of water or waterbody is any significant accumulation of water, usually covering the Earth or another planet. The term body of water most often refers to large accumulations of water, such as oceans, seas, and lakes, but it may also include smaller pools of water such as ponds, puddles or...

 (or their drainage basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

s) transcend international boundaries: ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

s, large marine ecosystem
Large marine ecosystem
Large marine ecosystems are regions of the world's oceans, encompassing coastal areas from river basins and estuaries to the seaward boundaries of continental shelves and the outer margins of the major ocean current systems...

s, enclosed or semi-enclosed regional sea
A sea generally refers to a large body of salt water, but the term is used in other contexts as well. Most commonly, it means a large expanse of saline water connected with an ocean, and is commonly used as a synonym for ocean...

s and estuaries, river
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s, lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

s, groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...

 systems (aquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...

s), and wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....


Oceans, seas, and waters outside of national jurisdiction are also referred to as the high seas or, in Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

, mare liberum (meaning free seas).

Ships sailing the high seas are generally under the jurisdiction
Jurisdiction is the practical authority granted to a formally constituted legal body or to a political leader to deal with and make pronouncements on legal matters and, by implication, to administer justice within a defined area of responsibility...

 of the flag state
Flag State
The flag state of a commercial vessel is the state under whose laws the vessel is registered or licensed.The flag state has the authority and responsibility to enforce regulations over vessels registered under its flag, including those relating to inspection, certification, and issuance of safety...

; (if there is one) however, when a ship is involved in certain criminal acts, such as piracy
Piracy is an act of robbery or criminal violence at sea. The term can include acts committed on land, in the air, or in other major bodies of water or on a shore. It does not normally include crimes committed against persons traveling on the same vessel as the perpetrator...

, any nation can exercise jurisdiction under the doctrine of universal jurisdiction
Universal jurisdiction
Universal jurisdiction or universality principle is a principle in public international law whereby states claim criminal jurisdiction over persons whose alleged crimes were committed outside the boundaries of the prosecuting state, regardless of nationality, country of residence, or any other...

Several international treaties have established freedom of navigation
Freedom of the seas
Freedom of the seas is a principle in the international law and law of the sea. It stresses freedom to navigate the oceans. It also disapproves of war fought in water. The freedom is to be breached only in a necessary international agreement....

 on semi-enclosed seas.
  • The Copenhagen Convention of 1857 opened access to the Baltic
    Baltic Sea
    The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

     by abolishing the Sound Dues
    Sound Dues
    The Sound Dues were a toll on the use of the Sound which constituted up to two thirds of Denmark's state income in the 16th and 17th centuries...

     and making the Danish Straits
    Danish straits
    The Danish straits are the three channels connecting the Baltic Sea to the North Sea through the Kattegat and Skagerrak. They transect Denmark, and are not to be confused with the Denmark Strait between Greenland and Iceland...

     an international waterway free to all military and commercial shipping.
  • Several conventions have opened the Bosporus
    The Bosphorus or Bosporus , also known as the Istanbul Strait , is a strait that forms part of the boundary between Europe and Asia. It is one of the Turkish Straits, along with the Dardanelles...

     and Dardanelles
    The Dardanelles , formerly known as the Hellespont, is a narrow strait in northwestern Turkey connecting the Aegean Sea to the Sea of Marmara. It is one of the Turkish Straits, along with its counterpart the Bosphorus. It is located at approximately...

     to shipping.