Bernhardt, Rudolf Keywords: International customary law | Law of the sea | Law of treaties | International law | Mots clefs: Droit coutumier international | Droit de la mer | Droit des traités | Droit international | ABSTRACT Rudolf Bernhardt, Director of the Max Planck Institute for Comparative Public Law and International Law in Heidelberg, notes that the combined play of custom and treaty, in the Law of the Sea, requires the consideration of general and theoretical elements and requires an attempt to link these general considerat…