International regimes almost always reflect two or more principles. In recent centuries the law of the sea has reflected a tradeoff between free access and national enclosure, and then recently a third principle, common heritage, was integrated into the regime. The relative prominence of these principles has been influenced by changing uses of the oceans, the distribution of benefits from alternative regulatory arrangements, and changes in the distribution of power. The 1982 United Nations Convention on the Law of the Sea represents a complex balancing of the three principles. The extension of coastal-state economic jurisdiction to 200 miles and the increased assurances of freedom of navigation have broad support, but the hybrid free-access/common-heritage regime for deep seabed mining has been challenged by some developed countries that favor greater weight for free access. These are, however, not likely to be the two alternatives. Rather they are likely to be a hybrid close to that in Part XI of the 1982 treaty and further national enclosure or the national lakes model. A central purpose of this article is to explore those forces and circumstances that could lead to the emergence of a national lakes regime. © 1990 Taylor & Francis Group, LLC.