The position of stateless vessels at international law

Abstract

This dissertation examines the legal position of stateless vessels under international law, focusing on whether statelessness permits the exercise of enforcement jurisdiction on the high seas. The analysis is situated within the framework of the law of the sea, as codified in the United Nations Convention on the Law of the Sea (UNCLOS), which allocates jurisdiction on the basis of vessel nationality and the principle of exclusive flag State jurisdiction. The study first analyses the concept of statelessness and its legal implications, emphasising the absence of a recognised link between vessel and State and the resulting exclusion from the protective regime of flag State jurisdiction. It then evaluates the treatment of stateless vessels under UNCLOS, demonstrating that while the Convention permits boarding through the right of visit, it does not establish a comprehensive legal basis for enforcement measures such as seizure, detention, or prosecution. The dissertation further examines treaty regimes addressing maritime migrant smuggling and drug trafficking, showing that these frameworks facilitate interdiction but remain grounded in cooperation and do not transform statelessness into an independent basis of enforcement jurisdiction. Through an assessment of State practice, particularly in the Mediterranean context, the dissertation demonstrates that statelessness operates as a practical trigger for interception but does not constitute a sufficient legal basis for enforcement action. Engagement with competing doctrinal approaches supports a restrictive interpretation, rejecting the view that stateless vessels are subject to universal enforcement jurisdiction and affirming that enforcement must be grounded in a recognised jurisdictional basis. The dissertation concludes that statelessness removes the protection of exclusive flag State jurisdiction but does not authorise enforcement jurisdiction on the high seas. This reflects a balance within the law of the sea between effective enforcement and the preservation of fundamental principles, while underscoring the need for greater clarity and cooperation in addressing maritime challenges.