Nevertheless, the Court accepted that Chile`s confidence in the provisions of various agreements from 1952 to 1954, in the context of the 1947 proclamations and the Santiago Declaration of 1952, was sufficient to conclude a tacit agreement for a parallel general maritime border No. 1. In this conclusion, the Court examined the practices of the parties in the early and mid-1950s, as well as the broader context, including the evolution of the era in the area of law of the sea. He also assessed the practice of both parties after 1954. The ICJ found that the pre-1954 practice and agreements « suggested an ongoing agreement between the contracting parties on their maritime border » (Peru/Chile, item 91). The Court also considered the 1954 agreement on offences committed by small fishing vessels at the maritime border. Article 1 of the 1954 agreement established a special zone « at a distance of 12 nautical miles from the coast, which extends 10 nautical miles across the parallel that constitutes the maritime boundary between the two countries. » The ICJ found that the 1954 agreement was an acknowledgement of the existence of a maritime border by the parties (although the agreement does not provide information on the nature or extent of that border). Acknowledging the cumbersome existence of the tacit agreement, the Court stated that at the beginning of the 20th century, some nations expressed their desire to extend national demands: the integration of mineral resources, the protection of fisheries resources and the provision of means of pollution control. (The League of Nations convened a conference in The Hague in 1930, but no agreement was reached.
 By applying the principle of a nation`s international law to the protection of its natural resources, President Harry S. Truman extended control of the United States in 1945 to all natural resources on his continental shelf. Other nations quickly followed suit. Between 1946 and 1950, Chile, Peru and Ecuador extended their rights to a distance of 200 nautical miles (370 km) to cover their Humboldt-Strom fisheries. Other nations extended their coastal seas to 22 km.  In 1960, the United Nations held the second United Nations Conference on the Law of the Sea (CNUNS II); However, the Geneva conference, which has been held for six weeks, has not created any new agreements.  In general, developing and third world countries participated only as customers, allies or dependent on the United States or the Soviet Union, without having a meaningful voice.  The delimitation of the border by the application of the parallel method of latitude required by Chile (rather than relying on Peru`s preferred equidistance principle) greatly increases the ocean area subject to Chile`s sovereignty and jurisdiction, while significantly reducing Peru`s.
The considerable economic impact for both countries, which sets the demarcation line, is easily visible. The water column of the coasts of Peru and Chile, known as Humbolt Electricity, is extremely rich in living marine resources.