On 27 May 2026, a Special Chamber of the International Tribunal for the Law of the Sea (ITLOS) delivered its judgment in The M/T Heroic Idun (No. 2) Case (Marshall Islands v. Equatorial Guinea), ruling in favor of the Marshall Islands. The Special Chamber awarded €2,000,132 ($2,322,000), representing the fine imposed on the master, and more than $12 million in damages, including $5.9 million for loss of hire and just under $4.2 million for non-material damage suffered by the crew. It is the highest award ever made by ITLOS.
 
The decision is of considerable significance to shipowners, flag states, charterers, and the wider maritime industry. It addresses head-on the limits of anti-piracy enforcement powers under the United Nations Convention on the Law of the Sea (UNCLOS or the Convention) and the sanctity of freedom of navigation and exclusive flag state jurisdiction, and cautions states against the detention of crews without legitimate grounds.
 
The Marshall Islands was represented by its agent, Meredith Kirby; Marshall Islands Attorney General Bernard Adiniwin; and counsel from Twenty Essex, Sir Daniel Bethlehem, Penelope Neville, Paolo Busco, Courtney Grafton, Manuel Casas, and Jaihui Huang, with assistance from Richard Gunn and the wider Reed Smith team, and Alexandra Couvadelli, Vice President, Gard (UK) Ltd.
   
This update summarises the key aspects of the judgment and considers its practical implications.

Background

The M/T Heroic Idun (the Vessel) is a very large crude carrier (VLCC) flying the flag of the Marshall Islands, owned by Idun Maritime Ltd. and managed by OSM Ship Management AS. On 7 August 2022, the Vessel arrived near the Akpo Offshore Terminal in Nigeria’s exclusive economic zone (EEZ) to load crude oil but the requisite authorisations were not in place and so the master moved to a waiting position while charterers arranged for the loading papers. On the evening of 8 August 2022, the Vessel was approached by a small craft whose AIS was turned off, causing concern among the crew that it could be a pirate vessel; the master declined to follow its instructions and proceeded further offshore. In the event it transpired that the small craft was a Nigerian navy vessel, the NNS Gongola. The Vessel subsequently drifted into the EEZ of São Tomé and Príncipe awaiting clearances. 
 
On 10 August 2022, Nigerian authorities sent WhatsApp messages and a note verbale to Equatorial Guinea, stating (wrongly) that the Vessel had attempted to load crude oil without approval and had raised a false piracy alarm to evade interception, requesting that Equatorial Guinea “track and arrest the vessel and hand them (both vessel and crew) over to the Nigerian Government.” On 12 August 2022, the Equatoguinean naval vessel Capitán David intercepted the Vessel in the EEZ of São Tomé and Príncipe, threatening the use of force, including announcing that it had “orders to shoot,” and diverted the Vessel to Luba Freeport on Bioko Island.  
 
The Vessel and the crew were detained for 92 days in Equatorial Guinea. The master was fined €2,000,132 by the Equatoguinean Ministry of National Defence for alleged violations of domestic merchant marine law, including sailing without authorisation in the EEZ of Equatorial Guinea. On 11 November 2022, despite the fine having been paid in full, the Vessel and crew were not released but instead forcibly transferred to Nigeria, where they were detained for a further period until 27 May 2023, when a plea bargain agreement was reached and the Vessel and crew were finally released.

Jurisdiction, admissibility, and exhaustion of local remedies

Equatorial Guinea argued that: (i) the Special Chamber does not have jurisdiction to make determinations regarding the alleged breaches, which Equatorial Guinea said fall outside the scope of the Convention; (ii) the claims advanced by the Marshall Islands are inadmissible on the basis of the “Monetary Gold” (indispensable third-party) principle, namely that Nigeria was an indispensable third party and that the legality of Equatorial Guinea’s conduct could not be determined without a prior examination of Nigeria’s rights and interests; and (iii) local remedies had not been exhausted in respect of the crew’s damages.

The Special Chamber rejected the arguments of Equatorial Guinea on all of the points above. With respect to the “Monetary Gold” principle, the Special Chamber clarified:

“The question is not whether Nigeria was legally entitled to request assistance from Equatorial Guinea to interdict the vessel but rather whether Equatorial Guinea, by seizing the vessel, acted in violation of the provisions of the Convention. Such judicial determination can be made independently from the conduct of Nigeria and the events that led to the seizure of the vessel.”

In relation to the exhaustion of local remedies, the Special Chamber noted that the parties do not dispute the prerequisite for the exhaustion of the local remedies rule to apply, namely that:

“[T]here must be a jurisdictional connection or link between the persons suffering the damage and the State alleged to be responsible for the wrongful act which caused the damage. In the absence of such jurisdictional connection, the local remedies need not be exhausted.”

In light of the above, the Special Chamber concluded:

“The crew’s presence in Equatorial Guinea was not the result of their own conduct or voluntary entry, but rather the consequence of Equatorial Guinea’s enforcement actions which have been challenged in the present case. In the view of the Special Chamber, a jurisdictional link cannot be established simply because individuals are present in a State’s territory owing to that State’s own contested conduct.

In the circumstances in which the M/T Heroic Idun and its crew were apprehended and detained in the present case, it cannot be said that the crew, by their conduct, assumed the risk that if they suffered an injury it would be subject to adjudication under the domestic jurisdiction of Equatorial Guinea. Therefore, there was no jurisdictional connection between Equatorial Guinea and the crew sufficient to trigger the exhaustion of local remedies rule.”

Freedom of navigation on the high seas

The Marshall Islands submitted that, by intercepting the Vessel on 12 August 2022 in the EEZ of São Tomé and Príncipe, forcing it to divert course to Luba anchorage, and detaining it there, Equatorial Guinea acted in breach of the Marshall Islands’ rights to freedom of navigation and exclusive flag state jurisdiction contrary to Articles 87(1), 90, and 92(1) of UNCLOS, having regard to Article 58(2). The Chamber unanimously upheld this submission. It found that the Capitán David caused the Vessel to change its intended course by threatening the use of force, which constituted a breach of freedom of navigation unless justified by the Convention or other international treaties. 

Equatorial Guinea contended that its seizure of the Vessel was carried out in accordance with its obligation to cooperate to repress piracy under UNCLOS, and that the interception and apprehension occurred as a result of cooperation pursuant to the Yaoundé Code, which seeks to operationalise the obligation of cooperation under Article 100 of the Convention in Central and West Africa.

The Special Chamber rejected this defence. It held that the Yaoundé Code cannot confer powers beyond those in the Convention on its signatories vis-à-vis non-signatory flagged vessels and cannot provide a legal basis for measures contrary to UNCLOS. While the duty to cooperate in repressing piracy under Article 100 exists, it does not provide an autonomous basis for seizure; rather, any apprehension must conform to Articles 101 to 107, read with Article 110.

Treatment of the crew and the principle of humanity

In addressing the treatment of the crew resulting from the actions of Equatorial Guinea, the Special Chamber commented:

“Equatorial Guinea bears responsibility for the injury caused by its internationally wrongful act, including the mistreatment of the crew and the procedural injustices imposed upon them during their detention in Equatorial Guinea, and attributable to the acts and omissions of the Equatoguinean authorities.”

Accordingly, the Special Chamber found that:

“The treatment of the crew, by Equatoguinean authorities, during their detention, including their forced transfer to a third State, was in violation of the rights of the Marshall Islands under the Convention.”

The decision therefore reinforces the principle that, under UNCLOS, the rights of the flag state extend beyond the vessel itself and encompass the protection of those serving on board. It further underscores that coastal states, in exercising enforcement powers, must do so in a manner consistent with international law standards of due process and humane treatment. The judgment serves as an important reminder that departures from those standards may engage international responsibility and expose states to claims for reparations under the Convention.

Practical considerations

The Special Chamber’s decision in favour of the Marshall Islands gives rise to several important implications for flag states, shipowners, and coastal states concerning the operation of UNCLOS and its impact on the maritime industry:

• Robust reaffirmation of freedom of navigation. The Special Chamber unanimously held that Equatorial Guinea’s interception of the Vessel in the EEZ of São Tomé and Príncipe, including by threatening force and diverting it to Luba Freeport, breached freedom of navigation under Articles 87(1), 90, and 92(1) of UNCLOS (as applicable to EEZs via Article 58(2)). Any physical interference with navigation of a foreign-flagged vessel, including compelling a change of course under threat, violates freedom of navigation unless justified by the Convention or other international treaties.
• The “Monetary Gold” (indispensable third-party) principle does not shield a respondent state. The Special Chamber rejected the argument that the case was inadmissible because Nigeria was not a party, holding that the legality of Equatorial Guinea’s conduct could be assessed independently of Nigeria’s rights and interests. A state that takes enforcement action against a foreign-flagged vessel on the basis of a request from another state cannot avoid accountability by arguing that the requesting state is an indispensable party.
• The duty to cooperate in repressing piracy does not confer autonomous enforcement powers. The Special Chamber confirmed that any enforcement action on grounds of piracy must conform strictly to Articles 101 to 107, read with Article 110. A coastal or third state cannot rely on a generalised duty of state cooperation to prevent piracy as a basis to board, seize, or divert a vessel without satisfying the specific enforcement conditions in the Convention.
• Forcible transfer of a vessel and crew to a third state constitutes a separate violation. The forcible transfer of the vessel and crew to Nigeria constituted a further violation of the Marshall Islands’ rights. A detaining state cannot divest itself of responsibility by transferring a vessel and crew to a third state. The rights of the flag state continue to apply, and such a transfer compounds rather than resolves the original breach.
• Flag states can assert claims for the treatment of crew. The mistreatment of the crew during detention was attributable to Equatorial Guinea and constituted a violation of the Marshall Islands’ flag state rights. Local remedies did not need to be exhausted because the crew’s presence was the direct result of Equatorial Guinea’s own contested enforcement actions rather than any voluntary act. This confirms that a flag state has standing to bring claims for crew mistreatment, and that the remedy exhaustion requirement does not apply where individuals are present in a state’s territory solely because of that state’s unlawful conduct.

Client Alert 2026-118