The Law of the Sea

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Podcast Transcript

The world as we know it is made up of 193 countries, Antarctica, and a host of territories.

However, between all of those places are the high seas or international waters, which are not controlled by anyone. 

But where do international waters begin? What can you do in international waters? And how close can you actually sail to another country?

Learn more about the Law of the Sea, how it was created, and what it stipulates on this episode of Everything Everywhere Daily.


When humans first started sailing on the seas, there were effectively no rules.

On land, kings and emperors wrote laws that determined what could and couldn’t be done. The sea, however, was a state of anarchy. 

I do mean anarchy in the very literal sense of the word. There were no laws or rules governing what happened on the high seas….and if there were, there were no ways to enforce them.

Eventually, over time, customs and traditions were developed that covered nautical issues and maritime disputes. 

Becoming a sailor meant possibly years of training, which involved learning the customs and traditions developed for sailing on the high seas. 

I’ve done many episodes where some modern innovation or tradition began in Ancient Rome. In the case of maritime law, that really isn’t the case, which is rather odd. 

The Romans eventually controlled all the territory surrounding the Mediterranean Sea, yet they never developed any explicit set of laws regarding the high seas. They did have laws regarding shipping and insurance, but that was about it. 

That wasn’t to say that the seas weren’t important to Rome; it certainly was, and it never resulted in anything that you could call maritime law. 

The first thing we can point to that would be an explicit maritime law would be during the Byzantine Empire. They created a legal framework known as the Rhodian Sea Laws, or as it was called in Greek,  the Nomos Rhodion Nautikos, which was written around the year 800.

We are quite certain that it existed because there are many references to it in other texts. Unfortunately, there are no surviving samples of the Nomos Rhodion Nautikos in existence.  

What we can surmise is that the Nomos Rhodion Nautikos probably dealt with shipping insurance and might have simply codified rules that the Phoenicians may have developed as early as 1000 BC. 

The oldest surviving text on maritime law is the Ordinamenta et consuetudo maris, which dates back to 1063. It was written in Trani, a significant trading port in the Adriatic Sea.

It is a legal framework for resolving disputes and ensuring fair practices in maritime trade.

There were other rules regarding shipping and maritime trade over the centuries, including the Laws of Wisbuy, the Rolls of Oléron, and many others. 

However, none of these actually dealt with the sea itself; they just delt with ships that sailed on the sea. Also, none of these were treaties or agreements between countries. 

Big changes in the legal status of the sea began during the Renaissance and the Age of Discovery. 

In particular, the 1494 Treaty of Tordesillas. The treaty between Spain and Portugal basically divided the world in two between the two countries. 

The treat was a modification of a Papal Bull issued by Pope Alexander VI issued the year before. The treaty created a Line of Demarcation about 370 leagues (approximately 1,770 kilometers or 1,100 miles) west of the Cape Verde Islands.

Spain was given the rights to all lands west of the line, which included most of the Americas. Portugal was given the rights to all lands east of the line, which included parts of Africa, Asia, and later Brazil.

This treaty would have been great if you were Spain or Portugal; however, absolutely everyone else in the world would have had no incentive to honor the division of the world between these two countries. 

In particular, the Dutch developed a countervailing theory about the high seas.

This view of the high seas was included in the 1609 book Mare Liberum by the Dutch philosopher Hugo Grotius


Grotius argued that the sea should be treated like the air. It belonged to no one. This principle was based on the idea that “Every nation is free to travel to every other nation and to trade with it.” 

Grotius was working for the Dutch East India Company when he wrote it, and was making a philosophical case for why the Dutch should be allowed to sail to the East Indies.

For ships from any nation to be able to travel, they all had the right of Innocent passage.

Here, I should explain what Innocent passage is because it is still a fundamental pillar of international law today. 

Innocent passage is nothing more than the ability to sail from one point to the next without doing anything else. It does not include fishing, stopping, firing weapons, gathering data, conducting surveys, or anything else.

Goritus’s argument was not universally accepted, especially not by the English. 

The English legal scholar John Selden wrote a response to Mare Librum in 1635. His book, Mare Clausum, or Closed Sea, argued that parts of the sea could be appropriated and defended as easily as land.

Basically, he didn’t like the idea of Dutch ships fishing right off the coast of England. 

This idea was expanded by the Dutch legal scholar Cornelius van Bynkershoek in the 1709 book De dominio maris, or The Dominion of the Sea.

He said that the range of a country’s territory into the sea was effectively the range of its best weapons. 

This was later calculated by the Italian Ferdinand Galiami, who determined that the best guns of that era could shoot a cannonball approximately three nautical miles. This, coincidently, is also the same approximate distance that an adult can see to the horizon when standing on the shore. 

This position that most European countries came to accept in the 18th century became known as the Three-Mile Rule. Under this rule, any coastal waters within three nautical miles of the coast were considered the sovereign territory of the country that bordered them.

This became known as the “cannon shot rule” due to how simple and intuitive it was. 

The ideas of Grotius, Selden, and van Bynkershoek merged to form the basis of the international order on the seas. Basically, the high seas belonged to no one, but the seas within three nautical miles were part of the territory of the country it was next to.

There were some exceptions, in particular, places where you had to sail within three nautical miles of the shore to pass through a strait.  Examples of this include the Straits of Magellan at the tip of South America and the Strait of Malaca between Singapore and Indonesia. 

The three-mile zone was the generally agreed-upon standard until the middle of the 20th century.


Technical innovations have made many of the past assumptions about international waters moot.

For starters, the distance a cannonball could fire was no longer relevant in a world with long-range artillery. More countries began to proclaim their territorial waters extending out a longer distance. 

There was also suddenly an issue with oil and mineral rights in the seabed, something which had never been considered before. 

Another consideration was what to do about pollution. If there was an oil spill, for example, how would impacted countries be compensated?

Likewise, fishing became much more intensive, and the ability of ships to deplete a nation’s fish stock became much more real. 

Before World War II, the League of Nations called a conference to establish an international order for the sea, but nothing came of it. 

Progress did not occur until after the war and the establishment of the United Nations. In fact, this area was considered to be one of the biggest reasons for the creation of the UN.

A series of conferences were held regarding the Law of the Sea, the first of which took place in 1958 and the second in 1960. This resulted in several treaties, which were signed in the mid-1960s. 

A much more comprehensive agreement was negotiated over a period of almost a decade, from 1973 to 1982. The result was the United Nations Convention on the Law of the Sea.

It didn’t go into effect until it was ratified by its 60th country, which took place in 1994 when Guyana approved it. 

As of the day of this recording, 168 countries and the European Union are parties to the treaty. 

The treaty spells out three different maritime zones each country has on the sea. 

The first is the territorial sea. This is the zone where every country has full sovereignty over the waters closest to it. This extends 12 nautical miles off the coast at low tide. Many countries changed their three nautical mile claims in the 20th century, and 12 nautical miles was the limit that was agreed upon. 

Extending 24 nautical miles from shore is called the Contiguous Zone. 

The Contiguous Zone is an area just outside of territorial waters where certain laws can be enforced. For example, if a ship filled with contraband or illegal migrants was heading towards shore, it could be stopped in the Contiguous zone. Likewise, action could be taken if a ship was dumping waste in the Contiguous zone. 

The final zone, which extends out 200 nautical miles from shore, is the exclusive economic zone or EEZ. 

The EEZ is a much larger area reserved for economic uses by nearby countries, such as fishing, oil and gas exploration, and undersea mining. 

Underlying all of these different coastal zones is the principle of Freedom of the seas.

Freedom of the Seas allows for the previously mentioned “Innocent passage” through territorial waters. Innocent passage applies to all vessels, including warships. 


Different interpretations of “Innocent passage” have caused incidents in the past, in particular during the Cold War when one side or the other wanted to prove a point by sailing unusually close to the shore of another country. 

I noted that most nations have ratified the Law of the Sea Convention. Most of the countries that haven’t ratified it are landlocked, but there are a few exceptions. Turkey, Syria, Venezuela, and Peru have all not ratified the treaty.

However, there is one country that hasn’t ratified it that really stands out: The United States of America.

The US has never ratified the Law of the Sea Convention. For forty years, it has been rejected by multiple presidential administrations and Congresses, which has been controlled by both parties.

The biggest argument has been that the US feels that the Law of the Sea Convention takes too much control over the economic development of oil, gas, and mineral resources out of the hands of the US. 

Despite not having ratified the treaty, the US does de facto adhere to almost everything in the treaty, they just haven’t formally ratified it. 

International law regarding the high seas is something that most people probably don’t think much about, yet it is one of the most important parts of international law and international relations. 

Having a coherent system of international agreements that cover how the seas are used allows for much of the world’s international trade and overall makes the world a much safer and more prosperous place.


The Executive Producer of Everything Everywhere Daily is Charles Daniel. 

The associate producers are Ben Long and Cameron Kieffer. 

Today’s review comes from listener oooooooooooooooo over on Apple Podcasts in the United States. They write:

Worthy of 1389 listens.

All the episodes are my favorite. (I am) proud to be a member of the Completionist Club, Southern California chapter. Tomorrow I start my journey over, so I can get my platinum membership to the clubhouse. Thank you Gary, for bringing a daily dose of entertainment and education.

Thank you, oooooo! When do you get your elite platinum status in the Completionist Club, remember to get your membership card and your lapel pin so you can show off to everyone else in the clubhouse. 

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