The delimitation of maritime space is among the most complicated problems in international law engaging vital economic, political, security, and other national interests and often gives rise to disputes. Moreover, delimitation implicates related global issues regarding the development and use of the World Ocean which should be dealt by all nations in a comprehensive manner. The essence and meaning of delimiting maritime boundaries lie in the fact that this helps to fix the boundaries of the territorial sovereignty of a State and its spatial (or functional) jurisdiction. Delimitation, meaning the identification of a State’s maritime and jurisdictional boundaries, creates a legal prerequisite for preventing potential damage to State interests. The international law of the sea allows certain discretion to States in fixing their external maritime boundaries (both State boundaries and those that define the sphere of coastal functional sovereign rights) when there are no overlaps between the legal ownership rights of two or more States. When such overlaps exist, States determine their maritime boundaries in accordance with the 1982 United Nations Convention on the Law of the Sea, which establishes the breadth of certain maritime zones. A similar interpretation and implementation of the rules which regulate the marking of maritime boundaries is a precondition for trust and cooperation between States. However, the progress of codification in this sphere shows that States tend to be cautious in their acceptance of general delimitation rules. One may characterize the delimitation of maritime boundaries in two important respects. The first concerns fixing external maritime boundaries when these are defined on the basis of a legislative act which complies with the rules of international law relating only international waters and deep seabed beyond of these boundaries. In this case delimitation does not interfere directly with interests of any particular State, whereas wrongful actions during the delimitation process may violate interests of the entire international community. The second aspect concerns a situation where delimitation proves to be the division of maritime space where the legal title of two or more States overlap (neighboring countries adjacent or opposite). The delimitation of maritime space between adjacent or opposite nations proceeds with special difficulty when it touches upon the material interests of coastal States and concerns the partition of natural resources (natural gas, oil, and others). The legal provisions regarding the marking of the outer boundaries of territorial waters, an exclusive economic zone (EEZ), and the continental shelf do not interfere with the rules for the delimitation of maritime boundaries between States with adjacent or opposite coasts (this approach, in particular, is established by Article 76(10), 1982 Convention).
Work is devoted to the International Court of Justice, the legal nature of its decisions. It was found that the practice of international courts leads to the Anglo-Saxon law is regarded as a source of law judicial precedent, and decisions of the International Court of the UN have set a precedent are usually legal nature.
Тhe practice of this Court сomprehensively analyzed to review the territorial disputes between states, during which it applies international treaty rules contra legem even in situations where the latter is sufficiently clear and specific.
The author claims that the reason for the defeat of Ukraine in the case of maritime delimitation in the Black Sea "Romania v. Ukraine" was firstly itself consent to the said case in the Court of the United Nations, and secondly, an erroneous legal position of Ukraine, based on the recognition of the status of Snake Island ignoring practices of the Court of Justice in this category of international disputes, thirdly, do not take all necessary actions for the formation of international custom accessories Ukraine disputed areas.
Derogation from resolution of territorial disputes by the International Court of Justice should be accepted as an important problem of international law. The delimitation of maritime space is one of the most complicated problems in international law engaging vital economic, political, security, and other national interests and often gives rise to disputes.
