Can coastal states authorize other states to board stateless vessels suspected of drug trafficking in their contiguous zone or EEZ?
Executive summary
Coastal states enjoy specific enforcement rights in their contiguous zone and exclusive economic zone (EEZ) under the law of the sea, but those rights traditionally apply to the coastal state itself and not to authorizing third states to board stateless vessels; sources describe coastal authority to board for certain violations and the centrality of flag-state jurisdiction without describing a clear rule allowing delegation to other states [1] [2]. U.S. domestic practice gives U.S. authorities broad boarding powers over vessels subject to U.S. jurisdiction [3] [4], but available sources do not mention a generally accepted international practice allowing coastal states to authorize other states to board stateless vessels in their contiguous zone or EEZ for suspected drug trafficking (not found in current reporting).
1. Coastal-state enforcement powers are limited and tied to specific legal regimes
Contemporary commentary on vessel boarding under the United Nations Convention on the Law of the Sea (UNCLOS) emphasizes a balance between coastal-state rights and freedom of navigation; the coastal state has enforcement jurisdiction to the extent UNCLOS and related rules permit (for example, in the contiguous zone to enforce customs, fiscal, immigration or sanitary laws and to address violations affecting the EEZ) but that jurisdiction is framed around the coastal State’s own enforcement, not automatic authorization of third states to act in its place [1] [2].
2. Stateless vessels are a special case — flagless but still governed by law of the sea principles
Sources note that jurisdiction over a ship has historically been linked to nationality; a stateless vessel (one not entitled to fly any state’s flag) presents enforcement opportunities because it lacks effective flag-state protection, yet the literature provided frames boarding authority in terms of coastal-state jurisdiction or flag-state rights rather than explicit third‑party deputation options [1]. The materials do not report an established international rule that a coastal state can routinely authorize another state to board a stateless vessel in its contiguous zone or EEZ for drug trafficking (not found in current reporting).
3. U.S. practice: sweeping domestic boarding powers, but different from international delegation
U.S. statutory and Coast Guard materials make clear U.S. officers exercise broad authority to board vessels “subject to the jurisdiction of the United States” and to make inquiries, inspections, searches and seizures under U.S. law; courts have upheld preventive boardings in some contexts [3] [4]. Those domestic powers illustrate how a coastal state can itself act; they do not in the provided sources demonstrate that a coastal state has the unilateral authority under international law to hand that power to another state to conduct boardings in its EEZ or contiguous zone.
4. Drug interdiction arrangements exist, but sources here do not document a rule of unilateral authorization
In practice, bilateral and multilateral counter‑drug agreements and cooperative frameworks (shiprider arrangements, law‑enforcement exchanges) are used to permit foreign boarding and enforcement. The set of sources supplied does not include any descriptions or texts of such agreements or an explanation that UNCLOS permits unilateral authorizations by a coastal state to a third state to board in the EEZ or contiguous zone; therefore the available record here cannot confirm that coastal states can generally authorize other states to board stateless vessels for drug trafficking absent specific agreements (not found in current reporting; p1_s1).
5. What the sources do confirm and where reporting is silent
The materials confirm: (a) coastal states have defined enforcement roles in contiguous zones and the EEZ tied to customs, immigration, fishing and environmental regulation [1] [2]; (b) U.S. authorities claim and exercise broad boarding powers over vessels subject to U.S. jurisdiction [3] [4]. The materials are silent, however, on an international-law principle authorizing a coastal state to delegate boarding authority to another state in its contiguous zone or EEZ specifically for drug interdiction—an important gap for any legal conclusion (not found in current reporting).
6. Practical takeaway and what to look for next
If you need a definitive legal answer for a particular incident, seek the text of any bilateral “shiprider” or law‑enforcement cooperation agreement in force between the coastal state and the boarding state, and consult UNCLOS provisions and state practice as reflected in treaty texts and case law—these are the mechanisms that in practice create lawful boarding authority beyond a coastal state’s own agencies (available sources do not mention specific agreements in this dataset; p1_s1). For U.S.-led operations, look to U.S. statutes and Coast Guard policy, which authorize U.S. boardings where U.S. jurisdiction applies [3] [4].