Answer
Under the United Nations Convention on the Law of the Sea (UNCLOS), the rights and responsibilities of a coastal state are divided across maritime zones measured from its baselines:
Responsibilities & Rights of Coastal States by Maritime Zone| Maritime Zone | Extent | Coastal State Rights | Coastal State Responsibilities & Duties |
| Territorial Sea | Up to 12 NM | Full sovereignty over the water column, air space, seabed, and subsoil. Can adopt laws governing navigation safety, environmental protection, and prevention of customs/fiscal/immigration/sanitary infractions. | Must not hamper innocent passage of foreign ships (Art. 24). Must give publicity to known navigational dangers within its waters (Art. 24). |
| Contiguous Zone | Up to 24 NM | Enforcement powers to prevent and punish violations of customs, fiscal, immigration, or sanitary laws committed within its land or territorial sea (Art. 33). | Does not exercise full sovereignty; must respect high seas navigational freedoms for foreign vessels. |
| Exclusive Economic Zone (EEZ) | Up to 200 NM | Sovereign rights for exploring, exploiting, conserving, and managing living/non-living natural resources (fish, oil, gas, wind/wave energy) (Art. 56). Exclusive jurisdiction over artificial islands/structures (Art. 60). | Conservation & Management: Ensure living resources are not over-exploited (Art. 61). Must grant other states access to surplus allowable fish stocks if harvesting capacity is not met (Art. 62). Must have due regard for the rights and freedoms of other states (e.g., freedom of navigation, laying submarine cables). |
| Continental Shelf | Up to 200 NM (or beyond under Art. 76) | Sovereign rights over seabed and subsoil resources (mineral, non-living resources, and sedentary species) (Art. 77). | Rights do not affect the legal status of the superjacent waters or airspace. Must not impede the laying or maintenance of submarine cables or pipelines by foreign states. |
General Responsibilities Across All Zones
Marine Environmental Protection (Part XII): Coastal states are obligated to protect and preserve the marine environment, enforce anti-pollution measures, and cooperate internationally to reduce pollution from land-based, atmospheric, or vessel sources.
Search and Rescue (Art. 98): Promote and maintain an adequate and effective search and rescue (SAR) service regarding safety at sea.
Marine Scientific Research (Part XIII): Facilitate and grant consent for foreign marine scientific research in the EEZ and continental shelf for peaceful purposes under normal circumstances.
Innocent Passage is the legal right granted to ships of all states (whether coastal or landlocked) to navigate through a coastal state's territorial sea without prior authorization, provided the passage is not harmful to the peace, good order, or security of the coastal state (Art. 17 & 19).