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

The UNCLOS stands for United Nations Convention on the Law of the Sea, also called the Law of the Sea Convention or the Law of the Sea treaty. It is the international agreement from the third United Nations Conference on Law of the Sea commonly known as UNCLOS III, between 1973 to 1982. The UNCLOS came into force in 1994, and defines the rights and responsibilities of nations, establishing guidelines for sea-related businesses, use of the world’s ocean, the environment and the management of marine natural resources.

Before the UNCLOS concept of “Freedom of the seas” from the 17th century was there, in which country rights were limited to 3 nautical miles of their coastline. In the early 20th century, because of increase in trade through the sea and to exploit more resources from the sea some nations expressed their desire to extend national claims of shorelines. Other reasons were also there like to protect marine stock livelihood, enforce pollution controls etc.


The first conference on the Law of the Sea was held in 1956 at Geneva, Switzerland (known as UNCLOS I). Because of which four treaties concluded in 1958.

  • Convention on the Territorial Sea and Contiguous Zone(came into force 1964)
  • Convention on the Continental Shelf (came into force 1964)
  • Convention on the High Seas (came into force 1962)
  • Convention on Fishing and Conservation of Living Resources of the High Seas(came into force 1966)

Many important issues were not discussed in it, besides this, it was considered a success.


The second conference by UN on the Law of the Sea was held in 1960. All developing nations and third world countries participated as clients, allies, or dependents of the US or USSR. Therefore the conference did not result in any new agreements.


The third conference on Law of the Sea was held in 1973, with more than 160 nations participated and lasted until 1982. The main issue varying claims of territorial waters, other issues were navigation, archipelagic status and transit regimes,  continental shelf jurisdiction, deep seabed mining, the exploitation regime, protection of the marine environment, scientific research, and settlement of disputes. The resulted convention came into force on 16th November 1994. The convention set the limit of varied areas, measured from a fastidiously defined ocean baseline. The baseline is the low water line along the coast as marked on the large scale chart official recognized by the coastal state. The areas are as follows: unclos water zone

  • Internal Waters: It includes all water and waterways inside the land side of the baseline(Inland Water). The country(that includes water body in its land) free to set laws, regulate the use of resources. Foreign vessels have no right of passage within internal waters without permission from that country. 
  • Territorial Waters: It includes 12 nautical miles from the baseline. The coastal state is free to set laws and regulate the use of any resource. The foreign country vessels were given the right of navigation, only innocent passage. The coastal country can suspend the passage of a vessel, if essential for the protection of their security. An innocent passage of any vessel can be defined as the passage which is not prejudicial to the peace, good order or security of the state. The passage of any vessel shall not be considered innocent if she is engaged in threat or use of any force against the state, any exercise of weapon, any act of collecting information related to defense and security, any fishing activity, or carrying out any research or survey.
  • Contiguous Zone: It includes an area beyond 12 nautical miles (from territorial baseline) to further 12 nautical miles of sea. The country can continue to enforce laws in customs, taxation, immigration and pollution in this are. In case of any infringement, the concerning authority can pursuit the offender. The right to a hot pursuit of an offender by any state (according to UNCLOS) is also explained further. 
  • Exclusive Economic Zones EEZ: It includes the area extended up to 200 nautical miles from the baseline. Within this area, the coastal state has sole exploitation rights over all natural resources. Foreign states have the freedom of navigation, laying submarine pipes and cables.
  • Continental Shelf: It is defined as the natural prolongation of the land territory to the continental margin’s outer edge. It includes the area from baseline to EEZ if natural prolongation doesn’t end there. But it may never exceed 350 nautical miles from baseline or area where the depth of seabed is more than 2500 meter and 100 miles far from the baseline.

unclos rule explainedAny state authority can pursue a vessel in case of any case of infringement. Provide that the infringement started within the state’s territory or territorial waters, or this infringement is about to occur within the state’s territory or territorial waters. This makes the contiguous zone a hot pursuit area. The right to hot pursuit includes:

  1. The hot pursuit of a foreign ship may be undertaken when the competent authorities of the coastal states have a good reason to believe that the ship has violated the laws and regulations of that state.
  2. Such pursuit must be commenced when the foreign vessel or one of its boat is within the internal waters, territorial sea or the contiguous zone of the pursuing state.
  3. A right of hot pursuit shall apply to violations in the EEZ or continental shelf, including safety zones around the continental shelf installations or of the laws and regulations of the coastal state.
  4. The right of hot pursuit ceases as soon as the ship being pursued enters the territorial waters of her own state or any other state.
  5. The right of hot pursuit may only be exercised by warships or military ships or any other ship clearly marked and identifiable as a ship on government service.
  6. Where a ship has been stopped or arrested outside the territorial sea in circumstances which do not justify the exercise of the right of hot pursuit, it shall be compensated for any loss or damage it might have sustained as a result of such stoppage or arrest.

Any act of piracy threatens maritime security by endangering, the welfare of seafarers and also the security of navigation and commerce. Sometimes these criminal acts lead to the loss of life, physical damage or hostage-taking of seafarers, important disruptions to commerce and navigation.  Therefore rules regarding piracy have also been covered in the Law of the Sea. The piracy defined as per UNCLOS :

  1. Any illegal acts of violence or detention, or any other act of depredation, committed for private ends by the crew or the passenger of a private ship or a private aircraft and directed.
  2. On the high seas, against another ship or aircraft, or against persons or property on board such ship or aircraft.
  3. Against a ship, aircraft, persons or property in a place outside the jurisdiction of any state.
  4. Any act of voluntary participation in the operation of a ship or of an aircraft with knowledge of facts making it a pirate ship or aircraft.
  5. Any act of initiating or of intentionally facilitating an act as described above.

On high seas, or in any other place outside the jurisdiction of any state, every state may seize a pirate ship, or a ship taken by piracy and under the control of pirates and arrest the persons and seize the property on board. The courts of the state which carried out the seizure may decide upon the penalties to be imposed, and also determine the action to be taken with regard to the ships or property, subject to the rights of third parties acting in good faith. When a ship seized on suspicion of piracy without adequate grounds, the state making the seizure shall be liable for any loss or damage caused by the seizure.

The United Nation has no direct operational role in the implementation of the Convention. The organizations such as the International Maritime Organization, the International Whaling Commission, and the International Seabed Authority ISA(was established by UNthe ) plays a vital role in the operation of UNCLOS.

Till now the USA has not ratified the UNCLOS. According to the part XI of the convention, The International Seabed Authority(ISA) will authorize the royalty for exploration and mining of the minerals on the seabed outside any state’s territorial water or EEZ, United State argue that this is unfavorable to the American economy and security interests. Due to this US refused to ratify this convention, although it expressed agreement with remaining provisions of the convention.

Its contents are divided into 17 parts, with 320 articles and 9 annexes. Some major articles related to ship industry are given below.

  • Article 90: Right to Navigation

Every state coastal or landlocked has the right to have its ships flying its flag on high seas.

  • Article 91: Nationality of ship

Every state should lay down conditions/requirement for granting it’s nationality, registration and the right to fly its flag. The ship has the nationality of the state whose flag they are entitled to fly. The state must issue to ships flying its flag documents to that effects. There should be a genuine link between the state and the ship.

  • Article 92: Status of the ship

Ships must sail under the flag of the one state and are subject to the jurisdiction of the flag state on the high sea. The permission for the change of flag is given only in the case of transfer of ownership or change of registry. Its also deems that a ship which uses two or more flags according to convenience will be treated as a ship with no nationality.

  • Article 94: Duties of the flag State
    1. Each flag state to effectively exercise its jurisdiction and control in administrative, technical and social matters over the ship’s flying its flag.
    2. Maintain a register of the ship.
    3. Assure jurisdiction under its internal law over each ship flying its flag and its master, officer, and crew in respect to administrative, technical and social mater concerning for ship.
    4. Take each measure for ships flying its flag as are necessary to ensure the safety of the sea with regards to:-
      • Construction, equipment, and seaworthiness of the ship
      • Manning of ships, labor conditions and training of crew (STCW and ILO Convention).
      • Use of the signals, the maintenance of communication and prevention of collisions such measure includes.
      • Each ship is surveyed before and after registration by a qualified surveyor of ships and has onboard such charts, nautical publications, navigational equipment and instruments for safe navigation of the ship.
      • Each ship is in charge of master and officer who possess an appropriate qualification in seamanship, navigation, communication, and marine engineering, and the crew is appropriate in qualification and numbers for the type, size, machinery and equipment of ship.
      • The master, officers, the crew are fully conversant with and required to observe the applicable international convention like MARPOL, SOLAS, COLREG, GMDSS etc.
    5. In taking above measures each state is required to conform to generally accepted international regulation, procedures, and practice, and to take any step which may be necessary to require their observance.
    6. A state which has clear grounds to believe that proper jurisdiction and control with respect to ship is not exercised may report the fact to the flag state, upon receiving such report flag state may investigate that matter and if necessary to take remedial action.
    7. Every state must cause an inquiry by a qualified person into every marine casualty/incident of navigation caused loss of life/damage to other nations or to the marine environment. The flag state and other states must cooperate in the conduct of the inquiry.
  • Article 217: Enforcement by the flag state
  1. Every state must adopt laws/regulation to ensure compliance of International laws by ships flying its flag.
  2. The state must take appropriate measures to prevent a vessel from sailing unless they are complying with International rule and standards regarding design, construction, equipment and manning.
  3. The state must ensure that the vessel is carrying on board all certificate by as per international requirement and must ensure periodical inspection of the ship for compliance.
  4. The state must provide an investigation when its vessel commit to a violation of international rule and regulation.
  5. The state should enforce its national law if sufficient evidence is there against its vessel.
  6. It should be prompt in responding to any request for information by any other state and it should be informed complaint international organization about the action taken.
  7. Flag state must fix the adequate penalty for any vessel which violates the law and the penalty must be adequate in severity to discourage future violations.
  8. Flag state should cooperate with other flag states if assistance is required.

Although With the help of the United Nation Convention on Law of the Sea the state interest and marine resources can be protected. One of the basic objectives of the UNCLOS is to resolve disputes among countries, but still, some issues are unresolved e.g. South China Sea island where many countries share the same territorial area of sea.

If you want to check out the full content of UNCLOS click here. Please do read our blog on IMO History.

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Abhishek Kumar

He is working as an engineer in Fleet Management Ltd. He is alumni of Marine Engineering & Research Institute (MERI) Mumbai. He loves writing blog & exploring new places. Specialty: Tankers and Bulk Ship

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