Three decisions on maritime boundaries in a period of 9 months during 1984-1985 have doubled the body of case law on the delimitation of ocean space. The cases decided by international tribunals prior to 1984 applied only to the continental shelf. The waters overlying the shelf were either part of the high seas or, if subject to coastal state jurisdiction, were left undivided as between neighboring coastal states. However, two of the decisions rendered last year—the decision by a Chamber of the International Court of Justice in the Gulf of Maine case and the one by an ad hoc arbitral tribunal in the Guinea/Guinea-Bissau case—constituted the first judicial determinations of boundaries that divide jurisdiction over both the continental shelf and the water column beyond the territorial sea. The decision by the International Court of Justice in the Libya/Malta Continental Shelf case represented the fourth in a line of cases delimiting the continental shelf alone.