The traditional freedoms of the high seas, set out in Article 87 of the 1982 United Nations Law of the Sea Convention, are now overlaid with a network of conventional international law provisions which seek to regulate a wide range of criminal activity, the taking of resources and environmental despoliation occurring on the high seas. Many of these regimes impose enforcement obligations on states parties but contain scant detail as to the practical mechanisms for enforcement. The high seas as an arena for maritime law enforcement presents new challenges for navies charged with implementing co-operative regimes. The development of uniform enforcement procedures and an equitable division of enforcement responsibility among regional navies or regional maritime security forces is essential if high seas regimes are to be implemented effectively. This article identifies some of the jurisdictional issues which can arise for navies or maritime security forces tasked with enforcing multilateral regimes beyond national jurisdiction.