Britannica AI Icon
Adding us as a Preferred Source tells Google you trust our content, so our articles show up more often in your Google Search, Discover feed, and AI Overviews.
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
Top Questions

How far does a country’s sovereignty extend into the ocean?

What is an exclusive economic zone?

What are the high seas?

What is the role of the International Seabed Authority?

The ocean, understood as the body of saltwater that covers nearly three-quarters of the Earth’s surface, is not literally owned by anyone or anything. Rather, its use as an avenue of transportation or shipment, as a vast body of natural resources, and as an object of scientific exploration or research is governed by a complex framework of international laws codified in 1982 in the United Nations Convention on the Law of the Sea (UNCLOS), which entered into force in 1994. Under UNCLOS, a country’s sovereign territory extends to a maximum of 12 nautical miles from its coastline, a portion of the ocean referred to as the country’s territorial waters. UNCLOS also permits countries with ocean coastlines to claim an exclusive economic zone (EEZ) extending up to 200 nautical miles from their shores, in which they have exclusive rights to exploit marine resources. Beyond the EEZs lie the high seas.

The high seas are unowned by any country and are considered international waters. They are open to all nations for navigation, fishing, and other activities, as long as they comply with international laws. The high seas are often referred to as a “global commons,” meaning they are shared resources that all countries have a right to use but also a responsibility to protect.

The International Seabed Authority (ISA), also established under UNCLOS, plays a crucial role in managing the mineral resources found on the ocean floor beyond national jurisdictions. Such resources, deemed the “common heritage of humankind,” and their exploitation is regulated to ensure that benefits are shared globally, particularly with developing countries. This framework aims to balance resource use with environmental protection and equitable distribution.