International waters are a concept that is often discussed but is also just as often misunderstood by people outside of marine industries.
Around half of the planet and a third of the oceans are owned by someone, either because they are internal waters such as rivers and lakes, the territorial waters, which span up to 12 nautical miles from the coast, or the exclusive economic zone, which extends up to 200 nautical miles.
A sea captain or shipping agent must know which waters are under which jurisdictions, or there can be major consequences. It can get quite complex as well since the exclusive economic zone is the rights to the sea bed and everything in the water but not the surface which is international.
However, the rest of the waters are known as international waters, or sometimes by the older expression high seas. These are waters that no country owns and typically the law that is followed is the law the ship is registered with, which is often (but not always) its country of origin.
There is a common misconception that because a ship is in international waters, there are no laws to stop you from doing anything, which is the opposite of the truth.
A ship either respects the law of its country of origin or in cases where a ship flies no flags, the law of any passing ship.
Certain international laws are enforced under the principle of universal jurisdiction, which means that any state can prosecute regardless of which flags they fly or where they do it.
This principle is used to stop piracy but is also used to stop acts of slavery and illegal broadcasting, as they are all crimes against international law.
International waters are fascinating and sometimes rather complex, but they are the opposite of the law-free zones that they are sometimes depicted as in fiction.
