The present article examines if the principle of freedom of the high seas as formulated by Hugo de Groot still plays a significant role in international law. The article starts from an analysis of De Groot's ideas on the law of the sea and then turns to the freedom of the high seas in the modern law of the sea. In both cases, the legal framework is assessed against the background of the activities that require(d) regulation. Freedom of the high seas, although it has lost ground to other ordering principles, remains significant at the level of principles. However, at the level of designing an effective regime for current problems in oceans management, which to a large extent are caused by deficiencies in the enforcement scheme implicit in freedom of the high seas, the writings of De Groot, in whose time those activities did not require any significant measure of international coordination and cooperation, offer little assistance.
To address the question how a future instrument for areas beyond national jurisdiction (ABNJ) might give consideration to the rights and obligations of coastal States and other States in establishing marine protected areas (MPAs) in ABNJ, the current article discusses the options that have been tabled in this respect in the preparatory meetings for the intergovernmental conference that will be negotiating that instrument. In considering the current legal framework, the focus is on the United Nations Convention on the Law of the Sea (LOSC), as the new instrument is to be elaborated under the LOSC and is required to be fully consistent with it. The article analyses the relevant practice of four specific regions that have established MPAs in ABNJ. The article concludes that due regard is fundamental in addressing interactions between coastal States and other States and considers some options to provide it with specific content.