International Waterways

Customary international law has never granted equal access and rights to countries that share navigable rivers either as boundaries between them or as waterways that traverse them successively. Freer use of international rivers has occurred in the nineteenth and twentieth centuries through the negotiation of treaties.

The St. Lawrence Seaway, opened for navigation by large ships in 1959, is an example of a legal and an administrative regime wholly devised and controlled by the two states (the United States and Canada) that share it. Based on a river in part, the seaway was developed with the construction of bypass canals, locks, and channel improvements, sometimes wholly within the territory of one state. In 1909, CANADA AND THE UNITED STATES consolidated and extended a number of earlier piecemeal arrangements in the Boundary Waters Treaty (36 Stat. 2448, 12 Bevans 359), to give both nations equal liberty of navigation in the St. Lawrence River, the Great Lakes, and the canals and waterways connecting the lakes. An international boundary line was drawn generally along the median line of the lakes (with some variation in Lake Michigan), but both nations were to exercise concurrent ADMIRALTY and criminal jurisdiction over the whole of the lakes and their connecting waterways. The admiralty jurisdiction reflected a disposition to treat the lakes as the high seas. This view was supported by the U.S. Supreme Court in United States v. Rodgers, 150 U.S. 249, 14 S. Ct. 109, 37 L. Ed. 1071 (1893), when it referred to the "high seas of the lakes."

The building of the St. Lawrence Seaway was complicated by the failure of Canada and the United States to negotiate an agreement for the creation of a joint international authority to supervise the project. Instead, each country established its own national agency to construct the canals, locks, and other works required for the 27-foot channel, making each agency responsible for work on its own side of the river. The agencies coordinated their work in a series of international agreements and informal arrangements. Where works extended over the international boundary, the two commissions allocated responsibility through the coordination of work at the technical level. They agreed on uniform rules of navigation, coordination of pilotage services, uniform tolls, and arrangements for collection.

Seagoing merchant vessels from other countries use the seaway regularly. Their right to do so rests not on any general principle of free navigation, but on national agreements and Article V of the GENERAL AGREEMENT ON TARIFFS AND TRADE, which mandates freedom of transit for merchant ships through the territories of signatories for traffic to or from the territory of other signatories. As the Great Lakes are inland waters and have been demilitarized since the Rush-Bagot Agreement of 1817 (T.S. No. 110½, 2 Miller 645, 12 Bevans 54), it is unlikely that foreign warships will request or receive permission to visit their ports.