The Court has no difficulty in finding that, for the purpose of measuring the breadth of the territorial sea, it is the low-water mark as opposed to the high-water mark, or the mean between the two tides, which has generally been adopted in the practice of States. This criterion is the most favourable to the coastal State and clearly shows the character of territorial waters as appurtenant to the land territory. The Court notes that the Parties agree as to this criterion, but that they differ as to its application.

Fisheries case, Judgment of December 18th, I951: I.C. J. Reports 1951, p.128.