Law of the Sea

Inland waters, as one of the maritime areas subject to the sovereignty of a state, is the part of the sea closest to the coast, and this area covers the area behind the line where the territorial sea begins. The State’s jurisdiction in inland waters is the same as its jurisdiction on land.

In determining where the inland waters end from the shore, the two procedures applied in determining the initial limit of the territorial sea shall be taken into consideration: 1. the procedure of baselines parallel to the shore connecting the points where the waters recede most at low tide; 2. the procedure of straight baselines connecting the appropriate points of the shore if the shore is indented and there are islands close to the shore. The following rules are applied when drawing this border: a) If there is a gulf where the boundary is drawn, the waters within this gulf shall be subject to the inland waters regime if the distance between the two ends of the gulf does not exceed 24 nautical miles; b) If there is a river at the starting point, the point where the waters recede the most from the mouth of the river to the sea at low tide shall be taken as basis; c) If there is a port here, the port facility at the most exposed port shall be taken into consideration in drawing the line; d) If there are islands close to the coast (if the distance from the coast is less than 24 miles), a straight line can be drawn from the headlands on the offshore side of these islands and the area behind this line can be included in the inland waters.

Turkish law does not stipulate any authorization requirement for commercial vessels, and the principle of freedom is adopted in this regard. The arrival of foreign warships in Turkish inland waters and ports is regulated in the 1983 Regulation on the Arrival of Ships of Foreign Armed Forces in Turkish Inland Waters and Ports and Their Movements and Activities in These Waters. The law stipulates that foreign warships must obtain permission 15 days in advance (30 days for nuclear ships). Permission must also be obtained for the crew of these ships to go ashore. Compensation for damages caused by these ships in inland waters and ports is requested from the flag state through diplomatic means.
Other legislation regulating the inland waters regime includes Law No. 618 on Ports, Law No. 4922 on the Protection of Life and Property at Sea, Customs Law No. 4458, Law No. 2548 on Ship Health Officials, Regulation on Waste Collection from Ships and Waste Control dated 2004, and Law No. 2565 on Military Prohibited Zones and Security Zones.

During the preparatory work for the 1982 Convention, Turkey argued that the adoption of
the 12-mile limit would effectively eliminate its continental shelf and economic zone rights in this region due to the islands in the Aegean Sea, change the high seas area in favor of Greek territorial waters (the high seas area would decrease from 51% to 29%), and eliminate Turkey’s ability to sail to the open sea. Turkey wants a treaty to determine the
Aegean Sea’s delimitation in an equitable manner. Since Turkey is not a party to the 1982 Convention, the 12-mile territorial sea rule cannot be applied to it. Moreover, even if 12 miles has become a customary rule, the said rule cannot be asserted against Turkey, which has openly and consistently objected to this rule from the beginning, due to the principle of “persistent objector”. Although both Turkey and Greece currently apply the 6 nautical mile territorial limit, Greece argues that the 1982 Convention gives it the right to extend its territorial waters to 12 nautical miles. Turkey, on the other hand, argues that the 12-mile rule does not apply to it.

When the issue of the width of territorial waters was discussed during the preparatory work for the 1982 Law of the Sea Convention, the majority of the states declared that they were in favor of a territorial sea width of 12 nautical miles, and as a result, Article 15 of the Convention adopted the provision that each state has the right to determine its territorial sea limits, provided that they do not exceed 12 nautical miles from the baselines.

Innocent passage is a continuous (including temporary stoppage due to breakdown or force majeure) and expeditious right of passage for the purpose of crossing the territorial sea without prejudice to the peace, order and security of the coastal state. Therefore, the coastal State has the authority to take necessary measures and prohibit non-innocent passage. According to the 1982 Law of the Sea Convention, actions that may render the passage harmful include: threat or use of force against the coastal State; military maneuvers and tests; boarding and lifting of aircraft; collection of intelligence and propaganda relating to the coastal state; loading and unloading of cargo and people in violation of the customs and immigration legislation of the coastal State; intentional and significant pollution of the sea; engaging in fishing; all kinds of research and survey activities; activities that may damage the facilities of the coastal State; any activity unrelated to the passage. Although the authority to assess whether the passage is harmful belongs to the coastal state, the ship state may object to this assessment and, if it is found to be right, may claim compensation for the damage it has suffered.

According to the 1982 Treaty’s contiguous zone regime, coastal states may establish a contiguous zone of up to 24 miles (12 miles of territorial sea + 12 miles of contiguous zone) from the baseline where their territorial sea begins to be measured. In this area, the coastal State may exercise the power of control necessary to prevent or punish violations of its customs, fiscal, immigration, or health legislation in its territory or territorial waters. The State may exercise its jurisdiction in this field only in respect of ships which, having committed the infringement in its territory or territorial waters, subsequently transit into the contiguous zone. What kind of measures can be taken in terms of the power of prevention is controversial, and according to one view, it authorizes investigation and search, but not arrest, of ships in this area if their conduct gives rise to suspicion that a violation of the above-mentioned legislation is about to be committed.

The 1982 Convention reorganized the regime regarding the passage through the straits. Accordingly, the sea routes used for passage between one part of the open sea (including exclusive economic zones) and another part of the open sea, or connecting the territorial waters of a state to the open sea, the waters of which are wholly included in the territorial waters of the coastal state or coastal states and used for international maritime transportation, are defined as international straits.

The Montreux Convention regulates the passage through the straits for merchant ships and warships according to four different conditions: a) In peacetime, foreign merchant ships, regardless of their flag and cargo, may pass freely, by day and by night without any formalities. They are only subject to a health inspection near the entrance of the straits and cannot be stopped during the passage thereafter. These ships may not be charged any fee other than the duty set out in Annex I of the Treaty. Pilotage and towing are optional. b) In time of war, when Turkiye is neutral, merchant ships shall be subject to the same rules as in time of peace. c) In times when Turkiye considers itself exposed to an imminent danger of war, merchant ships may be compelled to pass through the straits by day, to follow the route indicated by Türkiye and to take free pilotage. d) In time of war, when Turkiye is belligerent, merchant ships belonging to neutral states may pass through the straits provided that they do not aid the enemy and pass by day. However, Turkiye may control the cargo carried by these ships and may oblige them to follow a certain route and to take free pilotage.

According to the Montreux Convention, in the airspace over the straits, only civil aircraft have the right of passage over the route to be determined by Turkiye, between the Mediterranean and the Black Sea. Aircrafts making regular flights in this direction are obliged to give a general notice indicating the dates of passage.

The current regulation in Turkish domestic law that sets rules on the safety of passage through the straits and the prevention of pollution is the Regulation on Maritime Traffic Order in the Turkish Straits, which was enacted in 1998 and last updated in 2018. In this regulation, there are provisions for the ships passing through the straits to have the technical equipment specified in international conventions, to report on the navigation plan, to notify the administration in advance of the passage of ships of certain sizes and ships operating with nuclear power or carrying dangerous cargo, to comply with the traffic separation scheme established to ensure the safety of passage, to ensure that ships carrying dangerous cargo pass through the strait one by one, and to suspend the passage temporarily in certain circumstances (fog, current, etc.).

In the 1958 Continental Shelf Convention, this concept ceased to be a geographical definition as originally formulated and was defined as follows: a) the seabed and subsoil of the underwater areas adjacent to the coast but outside the territorial sea to a depth of 200 meters or extending beyond this to the point where the depth of the waters makes it possible to exploit the natural resources therein; b) the seabed and subsoil of the same underwater areas adjacent to the coasts of islands (not rocks). In its 1969 decision on the North Sea Continental Shelf, the UN Court of Justice ruled that the state has sovereign rights to exploit natural resources due to and as an extension of its territorial sovereignty in this area and that the rule on the continental shelf has become a customary rule.

Motivated by the need to delimit the area that can be exploited as a result of technological
developments, the 1982 Treaty introduced a different provision on the width of the continental shelf. According to this provision, the continental shelf of the coastal State shall include the seabed and subsoil extending beyond the territorial sea up to a maximum of 350 miles along the natural continental margin of the territorial sea or, if the continental margin is less than 200 miles, the area up to 200 miles from the baseline from which the territorial sea begins to be measured. In this way, the Treaty developed a new criterion for
determining the width of the continental shelf that takes into account both the geographical structure of the seabed and the distance. The Treaty also established a delimitation commission to examine and advise on claims beyond 200 miles.

On the continental shelf, the coastal state has exclusive sovereign rights arising from its sovereignty in the land territory. Therefore, these rights do not need to be claimed, declared, or exercised in order for them to arise. The rights here cannot be exercised by other states without permission. On the continental shelf, the coastal state exercises sovereign rights such as the exploration and exploitation of natural resources. These resources include minerals and other nonliving resources found on the seabed and subsoil, as well as living organisms that live or move in contact with the seabed. The coastal State has the right to take reasonable measures to prevent pollution in this area. Scientific research and drilling on the continental shelf require the permission of the coastal state. The coastal state may establish artificial islands and facilities for the exploitation of resources in this area and may establish a security zone with a radius of 500 meters around them. The continental shelf rights of the coastal state do not affect the high seas freedoms of transportation, flight, and others of states in the waters above the continental shelf and in the airspace adjacent to it. In terms of the right of other states to lay cables and pipes in the high seas, if they are to be installed through the continental shelf of the state, the work on the location of the passage of these pipes shall be carried out with the permission of the coastal state.

Turkiye declared an exclusive economic zone in the Black Sea by Decree of the Council of Ministers in 1986, and the boundaries of this zone were determined by a treaty with the Soviet Union in 1987 (based on the boundary established in the 1978 Continental Shelf Treaty). After the collapse of the Soviet Union, Russia, Ukraine, and Georgia declared succession to this Treaty. The border with Bulgaria was established by a 1997 treaty. No exclusive economic zone has been declared in the Aegean and Mediterranean.

The rights and powers of the coastal State in the EEZ are: a) the exploration, exploitation,
protection, and management of living and nonliving natural resources; b) the opportunities for exploitation for other economic purposes, such as the generation of energy from water, currents, and wind; c) the establishment of artificial islands, facilities, and similar structures; c) the conduct of scientific research on the sea; d) the protection of the marine environment. The coastal State is also authorized to establish a security zone with a radius
of 500 meters around artificial islands and facilities subject to its jurisdiction. The coastal state has the right to determine the amount of living resources (fish, etc.) to be fished in the EEZ, and the flag state of vessels in this area must exercise due diligence in taking measures to prevent unlawful fishing by those vessels. It has been recognized that the coastal State has the authority to board, search, arrest, and prosecute vessels in order to ensure compliance with the laws and regulations it has established in the exercise of its rights (except for customs matters) in the exploration, exploitation, protection, and management of living resources in the EEZ. However, the coastal state is obliged to release the arrested seafarers upon posting a deposit. Again, if a ship passing through the EEZ causes pollution that causes or threatens to cause significant (major) damage to the coastal State’s coast or its interests therein, or to its resources in its territorial waters or in the EEZ, the coastal State has the right to investigate and detain the ship (provided that it releases the ship upon deposit of security). 

The first treaty to codify the rules on freedom of the high seas was the 1958 High Seas Convention. It included the following freedoms for both coastal and non-coastal states to exercise on the high seas: a) freedom of transportation and navigation; b) freedom of fishing; c) freedom to lay submarine cables and pipes.

The high seas are maritime areas that are not included in the territorial waters of any state and are not under the sovereignty of any state. The principle underlying the high seas regime is the rule of freedom of the high seas, which derives its source from customary law. According to this rule, while a state is exercising its freedom of the high seas, it must refrain from any act that would prevent another state from exercising the same freedom. The criterion to be applied in the event of a conflict between the rights of two states in the exercise of the freedom of the high seas is the mutual “reasonable” limitation of these rights. This requires a balancing of the mutual benefits and harms of both states.

There are some exceptions to the rule that the flag State has exclusive jurisdiction on the high seas. These are: a) the power to prevent and punish maritime piracy; b) the power to stop and search ships on the high seas; c) the power to prevent unauthorized radio broadcasts; d) the power of hot pursuit. States may exercise these powers only over foreign merchant ships. This is because foreign warships and state ships are exempt and subject only to the authority of the flag state. These powers over foreign merchant ships may be exercised by the warships and aircraft of the relevant state or by the state ships and aircraft assigned for this purpose.

The development of technology enabling the exploitation of mineral deposits on the seabed has raised the question of who will benefit from these resources. In this context, the 1982 Convention recognized that the seabed and the resources beneath the seabed beyond the limits of national jurisdiction are the common heritage of mankind and that no sovereign rights shall be granted to states over them.