The Concept of Hot Pursuit at Sea

I. This memorandum examines the international law doctrine of hot pursuit at sea, its legal basis, constitutive elements, and limitations. It analyzes its application within the Philippine legal context, considering national legislation and jurisdictional challenges, culminating in practical remedies for enforcement agencies.
II. Definition and Legal Basis. Hot pursuit is a recognized exception to the fundamental principle of exclusive flag state jurisdiction on the high seas. It allows a coastal state’s law enforcement vessels to pursue a foreign vessel suspected of violating its laws within its internal waters, archipelagic waters, territorial sea, or contiguous zone, and to arrest it on the high seas. Its primary legal basis is Article 111 of the 1982 United Nations Convention on the Law of the Sea (UNCLOS), to which the Philippines is a party. This treaty provision reflects customary international law.
III. Conditions for the Commencement of Pursuit. Pursuit must be initiated based on a good faith belief, grounded on clear facts, that the foreign vessel has violated relevant laws of the coastal state. The pursuit must begin while the violating vessel, or one of its boats, is within the pursuing state’s: (a) internal waters; (b) archipelagic waters; (c) territorial sea; or (d) contiguous zone (if the violation relates to the rights for which the zone was established, e.g., customs, fiscal, immigration, or sanitary laws). A visual or auditory signal to stop must be given at a distance enabling it to be seen or heard by the foreign vessel. The pursuit must be continuous and uninterrupted.
IV. The Right of Hot Pursuit in Archipelagic Waters. For the Philippines, an archipelagic state, the right of hot pursuit is particularly crucial. Under Article 111(1) of UNCLOS and the Philippine Archipelagic Baselines Law (Republic Act No. 9522), hot pursuit may commence from Philippine archipelagic waters. This is vital for combating transnational crimes, such as drug trafficking and illegal fishing, which often occur within the archipelago.
V. Continuation and Termination of Pursuit. The pursuit may continue onto the high seas or into the exclusive economic zone (EEZ) of another state, provided it remains continuous. The right of hot pursuit ceases as soon as the pursued vessel enters the territorial sea of its own state or a third state. The act of stopping and boarding the pursued vessel on the high seas must be exercised with necessary and proportional force, consistent with international standards.
VI. Limitations and Protections. The doctrine is strictly construed. Failure to meet any conditionsuch as proper signal, continuity, or lawful commencementrenders the pursuit unlawful, potentially making the arresting state liable for damages. The use of force must be a last resort and must be strictly necessary and reasonable. Aircraft may initiate or assist pursuit but must actively participate until a surface vessel arrives.
VII. Philippine Domestic Law Interface. The Philippine Coast Guard (PCG) and other maritime law enforcement agencies derive their authority to conduct hot pursuit from UNCLOS, as incorporated into domestic law through the Philippine Fisheries Code (RA 10654), the Comprehensive Dangerous Drugs Act (RA 9165), and other relevant statutes. The PCG Law (RA 9993) mandates the PCG to enforce laws within Philippine maritime jurisdiction, implicitly encompassing hot pursuit operations.
VIII. Jurisdictional and Operational Challenges. Key challenges include: (a) the vast maritime area of the Philippines, straining surveillance and rapid response capabilities; (b) the “instantaneous” entry of pursued vessels into neighboring states’ territorial seas, especially in the congested waters of the Sulu-Sulawesi region; (c) the need for real-time coordination between the PCG, Philippine Navy, and other agencies; (d) evidentiary standards to prove the conditions for lawful hot pursuit were met; and (e) encounters with vessels engaged in gray-zone activities or purportedly entitled to sovereign immunity.
IX. Practical Remedies. To effectively and lawfully exercise the right of hot pursuit, the following practical remedies are recommended: (1) Enhanced Maritime Domain Awareness: Invest in integrated coastal radar systems, long-range patrol aircraft, and unmanned systems to detect violations early and establish the factual basis for pursuit. (2) Standardized Protocols and Training: Develop and drill clear, UNCLOS-compliant standard operating procedures (SOPs) for initiation, signaling, continuity, and use of force, ensuring all personnel are trained. (3) Pre-negotiated Cooperative Agreements: Pursue bilateral agreements with neighboring states (e.g., Malaysia, Indonesia, Vietnam) for streamlined communication and, where possible, simplified procedures for continued pursuit or handover upon entry into their territorial seas, respecting sovereignty. (4) Robust Evidence-Gathering: Equip pursuit vessels with automated data recording systems (voyage data recorders, continuous video) to document the violation, the signal to stop, and the continuity of pursuit for legal proceedings. (5) Inter-Agency Command Center: Establish a permanent, 24/7 joint maritime law enforcement command center to coordinate PCG, Navy, and PNP Maritime Group assets in real-time during pursuits. (6) Legal Preparedness: The Department of Justice should provide specialized training to prosecutors on building cases predicated on hot pursuit, ensuring all elements are properly alleged and evidenced to withstand judicial scrutiny.