Criminal Conduct on the High Seas: Is a General Rule on Jurisdiction to Prosecute Still Lacking?

This article aims to assess whether a general rule (whether conventional, customary or both) exists which determines the State (or the States) entitled to institute criminal proceedings against individuals who have committed criminal acts either on board or from a ship on the high seas. With regards to treaty law, and despite some ambiguities, it concludes that UNCLOS does not contain a residual rule determining which State (or States) is entitled to institute criminal proceedings against individuals who have committed an offense on board or from a ship on the high seas. As far as customary international law is concerned, the State practice examined confirms that current international law allows the exercise of jurisdiction by the courts of the flag State but considers that its jurisdiction concurs with that of other States having jurisdiction on the basis of different criteria as provided in their national legal systems.