Territorial waters

Territorial waters are special areas of water near a country's coast where that country has certain rights and rules. These areas include internal waters, the territorial sea, the contiguous zone, the exclusive economic zone, and sometimes the extended continental shelf. All these parts together are called maritime zones.

Ships have different rules depending on which of these areas they are passing through. These rules are set by the United Nations Convention on the Law of the Sea, one of the most agreed-upon treaties in the world. Beyond the exclusive economic zone, the waters are called the high seas, where countries cannot control what happens there.

Baseline

Main article: Baseline (sea)

The baseline is usually the line where the water is at its lowest point along the coast, as shown on official maps recognized by the coastal state. This line can be close to the shore or stretch out to sea if there are areas like mud flats that are sometimes covered by water.

Straight baselines can also be drawn between islands along a coast, across river mouths, or around bays. A bay is a clear bend in the coast that has enough land-locked water to be more than just a curve. The line drawn across a bay cannot be longer than 24 nautical miles.

Internal waters

Main article: Internal waters

Internal waters are areas of water that are close to the shore, like lakes, rivers, and bays. The country near these waters has full control over them and can make its own rules for any boats passing through.

For countries made up of many islands, such as Indonesia or the Philippines, the waters inside the outermost islands are also considered internal waters. These countries must allow safe passage for ships, but they can set specific routes for ships to follow. Each island can have its own shoreline line for these rules.

Territorial sea

The territorial sea is a strip of water up to 12 nautical miles (22 km) from a country’s coast. This area is part of the country’s territory, including the air above and the sea floor below. Even though it belongs to the country, ships from other countries are allowed to pass through peacefully, known as innocent passage.

Sometimes, countries disagree about where their territorial seas end. If two countries’ 12-nautical-mile lines overlap, the border is usually the middle point between them, unless they agree on something else. Countries can also choose to claim a smaller area for their territorial sea. There have been disagreements when one country claims a large area like an entire gulf as its territorial sea, which other countries do not accept.

Contiguous zone

The contiguous zone is a strip of water that stretches from the edge of a country's territorial sea out to up to 24 nautical miles. In this area, a country can enforce certain laws, such as those related to customs, taxes, immigration, and health, to protect its interests.

Usually, this zone is about 12 nautical miles wide. However, its width can change if a country’s territorial sea is smaller than 12 nautical miles, or to avoid overlapping with another country’s zone. Countries need to discuss and agree on solutions if their zones might overlap. The United States set its contiguous zone to 24 nautical miles from its baseline on September 29, 1999.

Exclusive economic zone

Main article: Exclusive economic zone

The exclusive economic zone (EEZ) is an area of water that stretches from the edge of a country's territorial sea out to about 200 nautical miles. In this area, the country can manage resources like fishing, mining, and oil exploration. However, other ships and aircraft may still pass through as long as they follow the country's rules.

Before rules were set, some countries tried to control more water to manage activities like oil exploration or fishing rights, leading to disputes such as the Cod Wars. Many people still mistakenly think the EEZ is part of a country's territorial waters.

Continental shelf

Main article: Continental shelf

Definition

The United Nations convention explains what a coastal country's "continental shelf" is.

A country's continental shelf goes out to the edge of its land under the sea but must be at least 200 nautical miles from where its territorial waters start, if the land under the sea doesn’t reach that far. Coastal countries can study and use the sea floor and what is on or under it. But other countries can lay cables and pipelines if the coastal country allows it. The farthest a country’s continental shelf can go is either 350 nautical miles from its starting line or 100 nautical miles from where the sea is 2,500 meters deep.

Extended continental shelf

Main article: Extended continental shelf

The part of the continental shelf that goes past the 200 nautical mile limit is called the "extended continental shelf". Countries that want to claim this area must give scientific information to a United Nations group. This group then checks the information and decides if the claim is valid. If countries have overlapping claims, they must talk to each other to solve it.

Countries have ten years after agreeing to the United Nations rules to make their claims for the extended continental shelf. Some countries have already made their claims.

Rights over the continental shelf

The rules explain what a country can do with its continental shelf.

A coastal country controls all resources on or under its continental shelf, whether they are plants, animals, or other materials, but it does not control anything living above the shelf that is outside its special economic zone. This means the country has the right to look for and collect oil and gas there.

Background

From the 1700s until the middle of the 1900s, many countries, including the British Empire, the United States, and France, claimed control over waters that were about three nautical miles (5.6 km) wide from their shores. This distance was chosen because it was far enough for a cannon to reach from land. Some other countries, like Iceland, Norway, and Sweden, claimed larger areas, while during some disagreements, nations claimed much bigger zones.

In 1987, the United Kingdom expanded its control to twelve nautical miles (22.2 km). In 1945, the United States made claims about resources near its coast. This led to international discussions about rules for these areas. It wasn’t until a big meeting in 1982 that a rule of twelve nautical miles was agreed upon, and it became official in 1994.

Miscellaneous

Pirate radio broadcasts from ships or structures in the water can be stopped by the nearby coastal country or other countries, no matter where the broadcast starts — whether in territorial waters, exclusive economic zones, on the continental shelf, or even on the open sea.

A coastal country has full control over its inner waters, a bit less over territorial waters, and even less over nearby zones. But it has full control over its natural resources in its exclusive economic zone and under its continental shelf.

In this article, distances in nautical miles are exact legal measurements, while distances in kilometres are just rough estimates.

Federal countries, like the United States, share control of some waters between the national government and individual states. (See tidelands.)

Territorial sea claim

Main article: List of territorial disputes

Countries have different rules about how far their waters extend from their shores. Some places set their limit at 6 nautical miles, like Greece and Turkey in the Aegean Sea. Most countries, such as Australia and Canada, set their limit at 12 nautical miles. A few places have special rules. For example, Australia has special agreements with Papua New Guinea about islands near their shared border. Peru calls its 200 nautical mile area its "Maritime Dominion."

Different countries have unique situations. The United Kingdom keeps a 3 nautical mile limit in some faraway territories but uses 12 nautical miles in others, like Bermuda and the Cayman Islands.

Contiguous zone claims

Different countries have different rules about how far their special water area, called the contiguous zone, stretches from their coast. Some countries, like Albania and the Bahamas, do not have a contiguous zone. Others, like Finland, have a zone that stretches 14 nautical miles from their shore.

Here are the distances for other countries:

• 15 nautical miles: Venezuela
• 18 nautical miles: Bangladesh, Gambia, Saudi Arabia, Sudan
• 24 nautical miles: Algeria, Angola, Antigua and Barbuda, Argentina, Australia, Belgium, Brazil, Bulgaria, Cambodia, Canada, Cape Verde, Chile, People's Republic of China, Cuba, Cyprus, Denmark, Djibouti, Dominica, Dominican Republic, Egypt, France, Gabon, Ghana, Haiti, Honduras, India, Iran, Ireland, Jamaica, Japan, Liberia, Madagascar, Maldives, Malta, Marshall Islands, Mauritania, Mexico, Morocco, Mozambique, Myanmar, Namibia, Nauru, The Netherlands, New Zealand, Nicaragua, Norway, Oman, Pakistan, Palau, Panama, Poland, Portugal, Qatar, Republic of Korea, Romania, Russia, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Samoa, Senegal, Seychelles, Sierra Leone, South Africa, Spain, Sri Lanka, Syria, Thailand, Timor-Leste, Trinidad and Tobago, Tunisia, Tuvalu, United Arab Emirates, United States of America, Uruguay, Vanuatu, Vietnam, Yemen
• 30 nautical miles: Italy
• 50 nautical miles: Democratic People's Republic of Korea (called the Military Boundary Zone)

Extended continental shelf claims

As of May 13, 2009, 51 requests from 44 countries were made to claim areas beyond their normal sea borders. Some countries made more than one request, and some worked together with others.

Recommendations were given for 8 of these requests. For example, the United Kingdom made a request for Ascension Island, but it did not succeed in extending its area beyond 200 nautical miles. Other countries like Australia, Barbados, Brazil, and France also made requests and received recommendations.