Maritime Dispute (Peru v. Chile)
Overview of the case
On 16 January 2008, Peru filed an Application instituting proceedings against Chile concerning a dispute in relation to “the delimitation of the boundary between the maritime zones of the two States in the Pacific Ocean, beginning at a point on the coast called Concordia . . . the terminal point of the land boundary established pursuant to the Treaty . . . of 3 June 1929”, and also to the recognition in favour of Peru of a “maritime zone lying within 200 nautical miles of Peru’s coast, and thus appertaining to Peru, but which Chile considers to be part of the high seas”.
In its Judgment of 27 January 2014, the Court examined whether, as claimed by Chile, there was an agreed maritime boundary extending 200 nautical miles from the Parties’ respective coasts. After analysing the proclamations and declarations of Peru and Chile (1947 Proclamations and 1952 Santiago Declaration), as well as later agreements and arrangements adopted by Peru, Chile and Ecuador, the Court concluded that the 1954 Special Maritime Frontier Zone Agreement acknowledged that a maritime boundary already existed, although that text did not state when and by what means that boundary had been agreed upon. The Court therefore considered that the Parties’ express acknowledgment of the existence of a maritime boundary could only reflect a tacit agreement they had reached earlier, and which was “cemented” by the 1954 Special Maritime Frontier Zone Agreement. Based on an assessment of all of the relevant evidence presented to it with regard to the agreed maritime boundary between the Parties, the Court concluded that the said boundary was an all-purpose maritime boundary and extended to a distance of 80 nautical miles along the parallel from its starting-point.
Having concluded that an agreed single maritime boundary existed between the Parties, and that this boundary started at the intersection of the parallel of latitude passing through Boundary Marker No. 1 with the low-water line, and continued for 80 nautical miles along that parallel, the Court applied the three-stage methodology it usually employs to determine the course of the maritime boundary from that point on. First, the Court constructs a provisional equidistance line unless there are compelling reasons preventing it from doing so. Second, it considers whether there are any relevant circumstances which may call for an adjustment of that line to achieve an equitable result. Third, the Court conducts a disproportionality test in which it assesses whether the effect of the line, as adjusted, is such that the parties’ respective shares of the relevant area are markedly disproportionate to the lengths of their relevant coasts.
The Court concluded that the maritime boundary between the Parties would start at the intersection of the parallel of latitude passing through Boundary Marker No. 1 with the low-water line, and extend for 80 nautical miles along that parallel of latitude to Point A. From that point, it would run along the equidistance line until it reached the 200-nautical-mile limit measured from the Chilean baselines (Point B). After that point, since the 200-nautical-mile projections of the Parties’ coasts no longer overlapped, the maritime boundary would run along the 200-nautical-mile limit measured from the Chilean baselines to Point C, where the 200-nautical-mile limits of the Parties’ maritime entitlements intersected. In view of the circumstances of the case, the Court defined the course of the maritime boundary between the Parties without determining the precise geographical co-ordinates. It recalled that it had not been asked to do so in the Parties’ final submissions. The Court therefore expected that the Parties would determine these co-ordinates in accordance with the Judgment, in the spirit of good neighbourliness. On 25 March 2014, Peru and Chile approved the co-ordinates of their maritime boundary.
This overview is provided for information only and in no way involves the responsibility of the Court.