As the possibilities for using the marine's riches have expanded, the problem of the relationship between coastal States and the sea, from a legal perspective, has become increasingly complex. The United Nations Convention on the Law of the Sea (UNCLOS), already in its preamble, reveals the desired spirit at the time of its conclusion (1982), that is, respect for the sovereignty of nations and the construction of a legal order for ocean spaces, aiming to facilitate the relationship between countries and support the desire for greater security in the various activities related to the ocean.

For this, the Convention brings a series of maritime spaces for the use of the States, delimiting competences and jurisdiction, in order to establish the desired legal security. According to the legal provision now under analysis, the sea can be delimited in Inland Waters, Territorial Sea, Contiguous Zone, Exclusive Economic Zone, Continental Shelf, High Seas and Area.

The jurisdiction of the coastal State can only be considered full over Inland Waters, a region in which the State is sovereign as if it was part of the continent, according to article 8 of the CNDUM. In other delimitations, the jurisdiction of the coastal State gradually decreases as the waters move away from the land region. In the Territorial Sea, the State has sovereignty, but its jurisdiction is limited, given the possibility of innocent passage of foreign ships in the region, as provided for in articles 17 et seq. of the UNCLOS, which is an international law that cannot be prevented by the coastal state. In such a case, civil and criminal jurisdiction rests with the flag State and not with the coastal State (although there are exceptions).

To carry out the delimitation of maritime spaces, the “baseline” was created, which is an imaginary line that separates the terrestrial region from the continent and the waters of the Territorial Sea. Inland Waters are those located within the baseline, so that, as previously stated, the State's sovereignty is complete there. From the baseline, the Territorial Sea is located, up to 12 nautical miles. In it, the State has sovereignty and rights of exploration, scientific investigation, police power, to promote navigation safety and to protect and preserve the marine environment.

It is important to note that the following spaces, the Contiguous Zone and the Exclusive Economic Zone, are regions in which the coastal State does not have sovereignty, but “functional” jurisdiction; that is, specific sovereign and jurisdictional rights. In these maritime zones, considered international waters for legal purposes, the State has specific rights, and cannot prevent the movement of vessels, unless they violate such rights.

In the Contiguous Zone, located 24 nautical miles from the baseline, according to article 33 of the UNCLOS, the State has inspection rights (customs, health, immigration and fiscal matters), as well as reprimand for violations of laws and regulations in its territory or in its Territorial Sea. In the Exclusive Economic Zone – EEZ, the functional character of the jurisdiction exercised by the coastal State is also evident, according to articles 55 et seq. of the UNCLOS. In it, the State has rights to explore, conserve and manage resources, up to 200 nautical miles from the baseline.

In the seabed and subsoil of the Exclusive Economic Zone, the Continental Shelf is located, which also extends to 200 nautical miles from the baseline, where the coastal State has the same rights of exploration of resources granted to the EEZ. There may be an extension of the Continental Shelf by up to 350 nautical miles from the baseline, pursuant to article 76, §5 of the UNCLOS.

From this delimitation, the High Seas begin, a maritime space where, according to article 89 of the CNDUM, no State can claim to be sovereign, so that it is a residual region (everything that does not constitute another maritime zone is considered high seas). The seabed and subsoil of waters beyond national jurisdiction are the Area, as per Part XI of the UNCLOS. Both the High Seas and the Area have “negative” concepts, that is, every oceanic part that is not jurisdictional water is considered to be High Seas, and every seabed that is not continental shelf is considered to be Area. In order to safeguard the biodiversity of the High Seas and the Area, it was decided by the United Nations, in 2023, the Agreement Under the United Nations Convention on the Law of The Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ).

References

UNITED NATIONS ORGANIZATION. United Nations Convention on the Law of the Sea. Jamaica, 1982. <https://www.un.org/depts/los/convention_agreements/texts/unclos/unclos_e.pdf>.