## Facts

- Denmark and the Netherlands sought delimitation of the North Sea continental shelf boundaries with the Federal Republic of Germany (Germany).
- The parties submitted the disputes to the International Court of Justice by Special Agreements (1967) requesting identification of applicable international law principles, not a drawn boundary.
- Germany was not a party to the 1958 Geneva Convention on the Continental Shelf; Denmark and the Netherlands relied on the Convention’s Article 6 equidistance method.
- Germany’s coastline is markedly concave compared to the adjacent coasts of Denmark and the Netherlands; strict equidistance would allocate Germany a relatively narrow shelf area and could exclude it from areas thought to contain oil and gas.
- The proceedings were joined because Denmark and the Netherlands were found to be “in the same interest,” and judgment was issued on February 20, 1969.

## Issues

1. Whether Article 6 of the 1958 Geneva Convention on the Continental Shelf, including the equidistance method, bound Germany by treaty or as customary international law.
2. Whether equidistance had become a general rule of customary international law applicable to non-parties.
3. What principles and rules of international law govern continental shelf delimitation among neighboring States in the North Sea.

## Decision

- The Court held Germany was not bound by Article 6 as a treaty provision because it was not a party to the 1958 Convention.
- The Court held the equidistance method had not crystallized into customary international law and was therefore not obligatory for Germany.
- The Court held delimitation must be carried out by agreement in accordance with equitable principles, so as to leave to each State the areas constituting the natural prolongation of its land territory under the sea.
- The Court declined to draw a boundary line and instead identified relevant considerations for the parties’ negotiations, including coastal configuration and avoidance of a cut-off effect.

## Legal Principles

- A treaty provision binds non-parties as custom only if there is sufficiently extensive and representative State practice and acceptance of the practice as legally required (opinio juris).
- The equidistance method is not inherent in continental shelf entitlement and is not automatically controlling absent proof of customary status.
- Continental shelf rights exist ipso facto and ab initio by virtue of sovereignty over the land; delimitation must respect each State’s natural prolongation.
- Maritime delimitation between neighboring States is to be achieved by agreement applying equitable principles in light of relevant circumstances, including coastal geometry and proportionality concerns, and should avoid results that unduly cut off a State from its shelf.

## Conclusion

The Court rejected mandatory equidistance as a customary rule binding on a non-party and required the parties to negotiate a continental shelf boundary based on equitable principles and natural prolongation, taking account of relevant geographic circumstances rather than applying an automatic method.


North Sea Continental Shelf (F.R.G. v. Den.; F.R.G. v. Neth.), Judgment, 1969 I.C.J. 3 (Feb. 20)