Story: Law of the sea

Page 1. Control of the oceans

All images & media in this story

The freedom of the seas

As soon as ocean-going ships were developed, the seas became a battleground, or a route to a battleground. Countries also began to claim ownership or control of oceans nearby. But it became clear that if the seas could be claimed in the same way as land territory, there was an increased potential for competition and conflict between countries.

As free as the breeze

In 1609 young Dutch legal thinker Hugo Grotius wrote the controversial Mare liberum, about the law of the sea. He proposed that ‘the sea, since it is as incapable of being seized as the air, cannot be attached to the possession of any particular nation’, and that ‘every nation is free to travel to every other nation, and to trade with it’. Mare liberum was later seen as the inspiration for the concept of ‘freedom of the seas’.

To reduce that risk, the legal concept of ‘freedom of the seas’ was developed in the early 17th century. The underlying philosophy was that the oceans were an infinite resource, and that anyone could exploit them, or use them for travel and transport. This became generally accepted for waters outside a ‘territorial’ sea of about 3 nautical miles from land.

The threat of conflict

International law based on freedom of the seas remained largely unchanged and unchallenged until the middle of the 20th century. But by then, many states with sea coasts realised that the relatively few countries with large naval, merchant or fishing fleets could engage in threatening or dangerous activities. They could also exploit fisheries or mineral resources such as oil, at great distances from their own shores and close to the coasts of other countries.

In response, a number of these coastal states began to claim ownership of, or exclusive fishing rights over, much wider territorial seas. Other states with little or no sea coast also sought a share in the resources. As a result the risk of widespread conflict over control of the seas and their resources re-emerged.

New Zealand’s changing perspective

Of all the livable places of any real size, New Zealand is one of the most isolated. It was also the last to be discovered. This isolation has had a profound effect on its attitude towards international management of the oceans, and their use as communication and transport highways.

In 1958 and 1960 the United Nations made largely unsuccessful attempts to address an increasingly unstable situation. New Zealand supported the maritime powers, notably the United States and Britain, in their efforts to preserve traditional open seas freedoms and to restrict the claims of coastal states. The country was conscious of its isolation and dependence on those freedoms for trade with its distant markets, especially Britain. It was also aware that as a member of Western defence alliances, its security relied on the wide-ranging deployment of naval forces.

But by the Third United Nations Conference on the Law of the Sea in 1974, New Zealand had established laws to protect coastal fisheries for a distance of 12 nautical miles from shore. A new view had emerged: New Zealand’s isolation could be turned to advantage. The country could control more resources, if the concept of an exclusive economic zone for coastal states gained international acceptance.

How to cite this page:

Bill Mansfield, 'Law of the sea - Control of the oceans', Te Ara - the Encyclopedia of New Zealand, (accessed 28 June 2017)

Story by Bill Mansfield, published 12 Jun 2006