Exclusive economic zone - Maritime Zones and Baselines

Maritime Zones: Understanding Coastal State Jurisdiction Introduction Coastal states have varying degrees of control and resource rights over the ocean and seabed adjacent to their shores. These maritime zones extend outward in concentric layers from the coastline, each with different legal rights and responsibilities. Understanding how to measure these zones and resolve disputes when they overlap is essential to international maritime law. The Baseline: Foundation for All Maritime Measurements Before any maritime zone can be established, we must first understand the baseline—the critical starting point from which all ocean zones are measured. The baseline is the line on a coastal state's shore from which the breadth of all maritime zones are calculated. Think of it as the official "edge" of the land where state jurisdiction begins to extend seaward. For most coasts, the baseline is simply the low-water line along the coast. However, for states with islands or irregular coastlines, determining the baseline can be complex, as it must be drawn in a way that encompasses bays and islands that belong to the state. The baseline is essential because every maritime zone discussed below—the territorial sea, the exclusive economic zone, and the continental shelf—all extend outward from this single point of reference. The Territorial Sea and Exclusive Economic Zone While not detailed in your outline, these zones form the immediate context for understanding the continental shelf and extended continental shelf. A coastal state's territorial sea extends 12 nautical miles from the baseline, where the state has full sovereignty. Beyond that, the exclusive economic zone (EEZ) extends 200 nautical miles from the baseline, where the state has special rights to explore and exploit natural resources but does not have full sovereignty. The map above shows how exclusive economic zones extend from coastlines around the world, illustrating the scale of maritime jurisdiction. The Continental Shelf: Extending Resource Rights into the Seabed The continental shelf is the submerged land area that extends from the territorial sea to the outer edge of the continental margin—the natural geologic shelf surrounding a continent. Unlike the EEZ, which is measured purely by distance from the baseline (200 nautical miles), the continental shelf is defined by geology: it is the actual seabed and subsoil that slopes gradually outward from the coast. Coastal states have special rights over the continental shelf to explore and exploit natural resources—particularly oil, natural gas, and minerals—found in the seabed and subsoil. These resource rights are granted regardless of whether the continental shelf extends beyond the EEZ boundary. The continental shelf can be considerably wider on some coasts than on others, depending on the underwater topography. The Extended Continental Shelf: Claims Beyond 200 Nautical Miles Some coastal states have continental shelves that extend significantly beyond the standard 200 nautical mile EEZ boundary. To address this, international law permits states to claim an extended continental shelf—resource rights over the seabed and subsoil extending up to 350 nautical miles from the baseline (in some cases, further under specific conditions). This is a crucial distinction: the extended continental shelf is not part of the exclusive economic zone. Rather, it is an additional claim to seabed resources beyond the EEZ. A state can exercise resource extraction rights (drilling for oil and gas, mining minerals) on the extended continental shelf, but it does not gain sovereignty over the water column itself or other activities in that region. For example, a state with a wide continental shelf might have: Exclusive Economic Zone: 200 nautical miles from baseline Extended Continental Shelf: from 200 to 350 nautical miles from baseline (for seabed resources only) The map above shows an example from the South China Sea, where multiple states have overlapping claims to maritime zones and contested areas. Notice how the various zones claimed by different countries overlap in the same geographic area. Handling Overlaps: Delimitation Rules In many parts of the world, maritime zones of neighboring states overlap. When two coastal states' exclusive economic zones or continental shelves would extend into the same area, the question becomes: who has rights there? International law provides a default rule: if exclusive economic zones overlap, the boundary defaults to the equidistant point—the line that is equidistant from both states' baselines—unless a bilateral treaty specifies a different boundary. This equidistant principle is fair in theory because it gives neither state an advantage. However, in practice, many neighboring states negotiate bilateral treaties to establish boundaries that differ from the strict equidistant line. These treaties may account for geographic factors, historic claims, or negotiated compromises that both parties find acceptable. The key point to remember: overlaps are resolved through either the equidistant default rule or through negotiated treaties between the states involved. This map of the Caribbean shows how numerous neighboring states each claim their own maritime zones, creating a complex patchwork of overlapping jurisdictions that have been resolved through various bilateral agreements. International Waters: Beyond All State Control International waters are those ocean areas that lie beyond any state's exclusive economic zone. These waters belong to no single state and are governed by international law applicable to all nations. States have rights to navigate, fish, and conduct scientific research in international waters, but these rights are balanced against the rights of other states. International waters are typically found in the deepest ocean basins, far from any continental shelf. They represent the "global commons" of the ocean—areas not subject to any state's control. <extrainfo> Additional Context: Real-World Examples Several regions illustrate the complexity of maritime zone delimitation: The South China Sea (shown in img2) represents one of the most disputed maritime regions, where China, Vietnam, the Philippines, and other states have overlapping claims to both EEZs and continental shelves. These disputes involve both boundary delimitation and competition for resources. The North Atlantic shows how some states (particularly those with wide continental shelves) have successfully claimed extended continental shelves and negotiated boundaries with neighbors through bilateral treaties. The Arctic Ocean presents emerging challenges as climate change reveals new potential seabed resources, leading to competition among Arctic states over continental shelf claims. </extrainfo> Summary Maritime zones create a framework for distributing ocean resources and jurisdiction. The baseline is the foundation from which all distances are measured. The territorial sea (12 nautical miles) and EEZ (200 nautical miles) represent the primary zones of coastal state authority. The continental shelf extends to the edge of the continental margin for seabed resource rights. The extended continental shelf can push claims to 350 nautical miles for seabed resources alone. When zones overlap, the equidistant line serves as the default boundary, though bilateral treaties often establish different arrangements. Everything beyond all states' EEZs is considered international waters, subject to the rights and responsibilities of all nations equally.