UNCLOS: Defining the Law of the Seas

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The Law of the Seas, or Maritime Law or Admiralty Law, is a comprehensive legal framework that governs activities and disputes related to the world’s oceans, seas, and navigable waters. It encompasses a wide range of issues, including territorial waters, navigational rights, environmental protection, resource management, and settling disputes related to sea activities. This body of law has been established to ensure the peaceful and orderly use and protection of marine resources, as well as to regulate maritime activities and resolve conflicts between nations. The Law of the Sea is crucial in regulating and maintaining order in the world’s oceans and ensuring the responsible use and conservation of marine resources. One of the most significant international agreements that shape the Law of the Seas is the United Nations Convention on the Law of the Sea (UNCLOS). It serves as the primary treaty governing these matters on a global scale. This article aims to provide an overview of maritime zones and highlight the key aspects of UNCLOS.  

United Nations Convention on the Law of the Sea (UNCLOS), 1982

The UNCLOS is a globally recognized treaty that serves as the primary legal framework governing the Law of the Seas. It is also known as the Law of the Sea Convention or the Law of the Sea Treaty. The same was adopted in 1982 and entered into force in 1994, with over 160 countries becoming parties to the convention. UNCLOS provides a comprehensive set of rules and principles for the management and conservation of marine resources, protection of the marine environment, settlement of maritime disputes, and the establishment and recognition of maritime boundaries. It promotes the peaceful and cooperative use of the seas and oceans, fostering international cooperation and diplomacy among states. The convention establishes the legal rights and obligations of states, as well as the rights and freedoms of other entities, including ships, coastal states, and landlocked states. UNCLOS also recognizes the importance of marine scientific research and the conservation of marine biodiversity, addressing issues such as pollution, piracy, and maritime boundaries. 

History and Formation of UNCLOS

The historical background and formation of the UNCLOS can be traced back to the early 20th century when discussions on the need for an international legal framework to govern the use and exploitation of the oceans and their resources began. One of the earliest significant events was the 1930 Hague Conference on the Codification of International Law, which addressed the issue of maritime boundaries and the concept of the territorial sea. However, due to various factors, including World War II and the subsequent Cold War, progress towards a comprehensive law of the sea treaty was slow. The 1958 Geneva Conventions on the Law of the Sea made some progress by codifying certain aspects of the law of the sea, including the concept of the territorial sea and the contiguous zone. However, these conventions did not fully address all the issues concerning the oceans and failed to gain widespread acceptance.

In the 1960s and 1970s, the need for a more comprehensive and universally accepted framework for the law of the sea became increasingly apparent. The rapid growth of offshore resource exploration, technological advancements in deep-sea mining, and growing concerns over pollution and the protection of the marine environment necessitated an international agreement that could address these challenges. The United Nations convened the first United Nations Conference on the Law of the Sea (UNCLOS I) in 1958 to discuss the issues related to the law of the sea. However, it did not result in a comprehensive treaty. UNCLOS II was held in 1960 but also failed to reach a consensus. Finally, in 1973, the General Assembly of the United Nations established the Third United Nations Conference on the Law of the Sea (UNCLOS III). The conference convened in 1974 and continued until 1982, resulting in the adoption of UNCLOS. The negotiations were complex and involved a wide range of issues, including territorial sea limits, maritime boundaries, navigation rights, resource exploitation, and the protection of the marine environment.

Maritime Zones

Maritime zones are specific areas of the ocean that are recognized and defined under international law. These zones are determined by their distance from a coastal state’s baseline, the low-water line along the coast. The primary motive behind these divisions is to manage and regulate various activities in maritime areas, such as navigation, resource exploitation, and environmental protection while respecting the rights and interests of coastal states and the international community. Maritime zones are bifurcated into the following regions as mentioned below:

  1. Territorial Waters: This is the area extending up to 12 nautical miles (approximately 22 Kilometers) from a coastal state's baseline. The coastal state has full sovereignty over these waters, including the airspace above and the seabed and subsoil below. Foreign vessels enjoy the right of innocent passage through the territorial sea, meaning they must navigate through these waters without engaging in any harmful activities to the coastal state's security or interests. The same is elaborated in Article 3 of the UNCLOS, 1982, which states that “Every State has the right to establish the breadth of its territorial sea up to a limit not exceeding 12 nautical miles, measured from baselines determined in accordance with this Convention.”
  2. Contiguous Zone: The contiguous zone extends to 24 nautical miles from the coastal baseline, approximately 44 kilometers. In this zone, a coastal state can exercise limited control for purposes like customs, immigration, fiscal, and pollution control. It allows the coastal state to take preventive measures to protect its interests, such as enforcing customs and immigration laws. The contiguous zone is defined under Article 33 of the UNCLOS, 1982.
  3. Exclusive Economic Zone (EEZ): The EEZ extends up to 200 nautical miles from the coastal baseline, approximately 370 kilometers. Within this zone, a coastal state has exclusive rights and jurisdiction over the exploration and exploitation of natural resources, both living and non-living, in the water column, on the seabed, and beneath its subsoil. Jurisdiction over the establishment, use of artificial structures, and research activities within this zone are also provided to the coastal states. However, foreign nations enjoy the freedom of overflight and navigation as well as the freedom to lay submarine cables and pipelines in this zone.
  4. Continental Shelf: The continental shelf extends beyond the EEZ and consists of the seabed and subsoil of the underwater landmass that extends from the coastal state's land territory. Coastal states have sovereign rights over the resources on their continental shelves.
  5. High Seas: The high seas are considered international waters where no single state has sovereignty and are beyond the 200 nautical mile limit of the EEZ. These areas are open to all states and are governed by international law, including the UNCLOS, and are subjected to specific principles of the same such as freedom of fishing, freedom of navigation, and freedom of scientific research. This area is preserved for peaceful purposes and all the states are only allowed to sail their ships on the high seas if they are flying their flag on the ship. 

Some other important terms related to the law of the seas include:

Internal Waters: Water and waterways on the landward side of the baseline of the territorial sea are referred to as the internal waters. Being an integral part of the coastal state’s territory, the coastal states exercise full sovereignty including the right to enforce laws, exploit resources, and regulate navigation. The right of innocent passage is not given to foreign vessels in case of internal waters whereas to do the same foreign vessels require permission for entry from the coastal state. 

Archipelagic States and Archipelagic Waters: The waters enclosed by the archipelagic baselines of an archipelagic state are known as the Archipelagic waters. As per Article 46 of the UNCLOS, 1982, an Archipelagic state means “a state constituted wholly by one or more archipelagos and may include other islands; archipelago means a group of islands, including parts of islands, interconnecting waters and other natural features which are so closely interrelated that such islands, waters, and other natural features form an intrinsic geographical, economic and political entity, or which historically have been regarded as such.” Archipelagic waters include both the waters within the archipelagic baselines and the waters between the islands. They are treated as internal waters, granting the archipelagic state complete sovereignty and control. However, the rights of innocent passage and archipelagic sea lanes passage are recognized for foreign vessels through designated routes within archipelagic waters, ensuring freedom of navigation. 

International Tribunal for the Law of the Sea (ITLOS)

ITLOS is an independent judicial body established under the UNCLOS to adjudicate disputes related to the interpretation and application of UNCLOS as well as other agreements and conventions concerning the law of the sea. It was formed on an official order, passed at the UNCLOS III. ITLOS consists of 21 members elected by states party to UNCLOS on the grounds of immense knowledge and ability to resolve matters in connection with the LOS (Law of the Sea). The members serve a term of nine years and represent a diverse range of legal systems and geographic regions. The tribunal operates based on the principle of equitable representation, ensuring fair participation of states from different regions of the world.

ITLOS has jurisdiction over various types of disputes, including those concerning the interpretation or application of UNCLOS, disputes related to the delimitation of maritime boundaries, and cases involving violations of the provisions of UNCLOS or other international agreements on the law of the sea. It provides a formal forum for states to resolve their maritime disputes peacefully and in accordance with international law whereas its decisions are binding on parties involved. It also has the power to grant provisional measures to preserve the rights of parties pending the final resolution of a dispute.    

Marine Pollution and Environmental Protection

Marine pollution refers to the introduction of harmful substances, such as oil spills, plastic waste, and chemical contaminants, into the oceans and seas, which can have devastating impacts on marine ecosystems, wildlife, and human health. Protecting the marine ecosystem is vital as the oceans play a crucial role in regulating the Earth's climate, providing oxygen, and supporting biodiversity. Marine pollution not only harms marine life but also affects human health, livelihoods, and economies. Additionally, environmental protection is essential to safeguard air quality, water resources, and terrestrial ecosystems. UNCLOS also highlighted certain provisions for the development of management and conservation measures concerning marine resources. Article 192 of the UNCLOS illustrates that “all states have the obligation to protect and preserve the marine environment.” Also, Article 194 of the UNCLOS listed certain “measures to prevent, reduce, and control pollution of the marine environment.” Apart from this, UNCLOS also provides provisions related to the ‘conservation of the living resources within the EEZ’ and the ‘conservation of the living resources of the High Seas’.

Doctrine of Hot pursuit

The concept of hot pursuit is described under Article 111 of the UNCLOS, 1982, which allows a state's law enforcement vessels to chase and apprehend a foreign vessel that has committed a crime or violated laws within the jurisdiction of the pursuing state. The doctrine of hot pursuit is an exception to the principle of freedom of navigation and is subject to strict limitations to avoid abuse. It is designed to balance the interests of the pursuing state with the rights and safety of the pursued vessel and its crew. According to the doctrine, hot pursuit is permissible when specific conditions are met which are as follows:

  • The pursuit must be continuous and uninterrupted from the initial sighting of the offending vessel until its capture or until it enters the territorial sea or port of another state.
  • There must be a reasonable ground to believe that a crime or violation of law has been committed.
  • The pursuit must be proportionate and necessary to prevent the escape of the offending vessel and protect the interests of the pursuing state.
  • The pursuing state should promptly inform the flag state of the pursued vessel about the reasons for the pursuit and the actions taken.

Overall, the doctrine of hot pursuit serves as a legal mechanism to address maritime crimes and violations, allowing states to take necessary action to maintain security and uphold the rule of law in the maritime domain.


Today, maritime law is a complex and multifaceted field encompassing a wide range of issues such as navigation, shipping, fisheries, piracy, environmental protection, and more. The Law of the Seas, with its various maritime zones and the UNCLOS, provides a comprehensive legal framework that ensures the equitable and sustainable use of the world's oceans and seas. By defining the rights and obligations of states, promoting cooperation, and resolving disputes, this body of law plays a crucial role in maintaining peace, fostering international relations, and protecting the marine environment. As the world continues to face new challenges in the maritime domain, the Law of the Seas and UNCLOS remain essential tools for upholding order and promoting the responsible stewardship of our shared oceanic resources.

1. What do you understand by baseline?
2. When was the United Nations Convention on the Law of the Seas (UNCLOS) adopted?