The law of the sea gives every coastal nation specific rights over the waters adjacent to its landmass. This authority is not unlimited, but it is clearly defined under international law. The United Nations Convention on the Law of the Sea (UNCLOS) governs these rights, offering a structured approach to how states manage and protect their marine resources.
Let’s explore how jurisdiction works over different maritime zones and what legal rights coastal states enjoy.
What Are Coastal Waters?
Coastal waters include areas of the sea that stretch from a country’s shoreline outward. These waters are divided into several zones:
- Internal Waters
- Territorial Sea
- Contiguous Zone
- Exclusive Economic Zone (EEZ)
- Continental Shelf
Each zone grants a different level of control and responsibility to the coastal state.
Internal Waters
Internal waters lie on the landward side of a nation’s baseline. These include bays, rivers, and ports. States have complete sovereignty over these areas, just like they do on land.
Foreign ships cannot enter internal waters without permission. The coastal state can enforce all domestic laws—criminal, civil, immigration, customs—without restriction.
Territorial Sea (Up to 12 Nautical Miles)
The territorial sea extends up to 12 nautical miles from the baseline. Within this area, the coastal state enjoys full sovereignty, including over the airspace above and seabed below.
Foreign vessels may enjoy the right of innocent passage—they can cross through the territorial sea as long as they do not threaten the peace, security, or environment of the coastal state. Still, the coastal state can regulate shipping routes and suspend innocent passage when necessary.
Contiguous Zone (Up to 24 Nautical Miles)
Beyond the territorial sea lies the contiguous zone, which extends up to 24 nautical miles from the baseline. In this zone, a coastal state does not have full sovereignty but can exercise control to:
- Prevent and punish violations of customs, immigration, fiscal, and sanitary laws
- Inspect ships for illegal activities before they reach its shores
This preventive jurisdiction ensures the coastal state can protect its borders and enforce national laws just outside its sovereign territory.
Exclusive Economic Zone (EEZ) – Up to 200 Nautical Miles
The EEZ extends 200 nautical miles from the baseline. Within this zone, a state does not have full sovereignty, but it enjoys special rights regarding:
- Exploration
- Exploitation of marine resources (fish, oil, minerals)
- Energy production from wind and water
Here, the coastal state can regulate fishing, environmental protection, and resource use. Other countries may still conduct peaceful navigation or scientific research but must respect the rights of the coastal state.
Coastal state rights under international maritime law allow nations to secure resources and manage oceanic activities within the EEZ. This balance between exclusive rights and international freedom of navigation is a key feature of UNCLOS.
Continental Shelf
The continental shelf refers to the seabed and subsoil beyond the territorial sea, extending to the natural prolongation of a state’s land territory, or up to 200 nautical miles, whichever is greater.
Coastal states have sovereign rights for exploring and exploiting the natural resources of the shelf. However, they cannot stop ships or submarines from traveling through the water column above, unless within their territorial sea.
Legal Framework: UNCLOS
The United Nations Convention on the Law of the Sea (1982) serves as the legal foundation for maritime jurisdiction. Almost all coastal states are parties to UNCLOS, which outlines the rights and responsibilities of countries in managing their maritime zones.
The convention ensures that coastal states can safeguard their economic and environmental interests while respecting international principles like freedom of navigation.
Limitations on Coastal State Jurisdiction
While coastal states enjoy extensive rights, international law imposes certain restrictions to balance global interests. For example:
- Coastal states cannot claim sovereignty beyond the 12 nautical mile territorial sea.
- Innocent passage must be respected within territorial waters.
- Foreign vessels have freedom of navigation and overflight in the EEZ and high seas.
- Military ships may not be stopped unless they violate specific national laws or environmental rules.
These checks ensure the ocean remains a shared and cooperative space.
Dispute Resolution
Jurisdictional disputes often arise between neighboring coastal states, especially over overlapping EEZs or fishing zones. UNCLOS provides mechanisms for peaceful dispute resolution through:
- The International Tribunal for the Law of the Sea (ITLOS)
- International Court of Justice (ICJ)
- Arbitration panels
These bodies help ensure that maritime boundaries and jurisdiction claims follow international norms.
