The geographical dimension of piracy and armed robbery against ships reveals gaps in the legal transposition between maritime and terrestrial spaces under French law. While international law, notably through Article 101 of the United Nations Convention on the Law of the Sea (UNCLOS), regulates piracy on the high seas, France has only partially transposed these provisions, omitting essential elements such as armed robbery at sea. This partial transposition is accompanied by the removal in French law of the concept of terra nullius, complicating jurisdictional attribution for acts committed outside territorial jurisdiction. Moreover, the interpretation of the concept of “jurisdiction” varies, causing confusion regarding the extraterritorial application of criminal law. This situation leads to problems of reciprocity, particularly concerning judicial cooperation or extradition with states such as Peru, El Salvador, Ecuador, Benin, Somalia, or Togo. Ultimately, the imperfection of the transposition and the ambiguity of concepts undermine the legal effectiveness in repressing acts of piracy or related offenses committed at sea.