The Law of the Sea and Disruptive Protests Against Deep Seabed Mining: The MV Coco Events

The Law of the Sea and Disruptive Protests Against Deep Seabed Mining: The MV Coco Events

[Eduardo Cavalcanti de Mello Filho is a Research Associate (Ocean Law and Policy) at the Centre for International Law, National University of Singapore]

The Context

Between 22 November and 4 December 2023, Greenpeace launched high seas protests against the Danish-flagged MV Coco, involved in deep seabed exploration and operated by Nauru Ocean Resources Inc (NORI). Sponsored by Nauru, NORI was exercising its rights as provided for in a contract with the International Seabed Authority (ISA). Notably, while Greenpeace protests directed against deep seabed mining on the high seas are not new, the MV Coco events represent an unprecedented escalation in the level of interference with activities in the international seabed area (“Area”). Greenpeace’s actions using the Dutch-flagged Arctic Sunrise included unauthorized boarding of the MV Coco via fast recovery crafts (FRCs) and serious interferences with its operations. 

A few days ago, the ISA Council considered these events in its 29th Session (18-29 March 2024). To justify its actions before the Council, Greenpeace cited the Arctic Sunrise arbitral award, invoking the right to protest at sea as a “lawful use of the sea related to the freedom of navigation” (p. 5). Yet, a number of delegations, more emphatically China, Japan, and Russia, understood that protest at sea could not interfere with rights in the Area (pp. 6-8)

In this post, I cover, from a law of the sea perspective, the relationship between the right to protest at sea and rights concerning activities in the Area in this particular case. First, I argue that the right to protest on the high seas is exercised through the freedom of navigation, which is a negative right. This means that non-flag States cannot subject a ship exercising that freedom to their jurisdiction. As such, by definition, freedom of navigation does not come into conflict with positive rights, such as those enjoyed by NORI. Second, and based on the above, I find that the Arctic Sunrise unduly interfered with NORI’s exercise of rights concerning activities in the Area. Third, I conclude that the Netherlands breached its flag State due diligence obligation to ensure that Dutch ships do not interfere such rights.

I will not address other critical issues in the realm of Dutch and Danish domestic legal orders, including their interactions with the European human rights system, or the competence of the ISA and its organs.

Protest as Comprised in the Freedom of the High Seas: A Negative Right

It is important to remark from the outset that we are dealing with protest as provided by the freedom of the high seas, not as a human right. Article 87(1) of the UN Convention on the Law of the Sea (“UNCLOS”) provides for the “freedom of the high seas,” which comprises, inter alia, freedom of navigation. Cited by the Netherlands (para. 12), Nauru (para. 2.1), and Greenpeace (p. 5), the Arctic Sunrise arbitral tribunal found that “[p]rotest at sea is an internationally lawful use of the sea related to the freedom of navigation.” To sustain this finding, the tribunal referenced international human rights instruments (para. 227). 

Generally, a ship exercising freedom of navigation cannot be subjected to foreign enforcement or prescriptive jurisdiction (Norstar, para. 225; but see the major dissent regarding prescriptive jurisdiction, para. 28). This is a prohibition on other States and the correlated negative right of the flag State. Hence, regarding the MV Coco events, the Netherlands only had the negative right not to have the Arctic Sunrise subjected to foreign jurisdiction while protesting at sea, but this exercise is not without its limits.

According to Article 87(2), this freedom “shall be exercised with due regard for the interests of other States in their exercise of the freedom of the high seas, and also with due regard for the rights under this Convention with respect to activities in the Area.” (Emphasis added.) The difference between “interests” and “rights” in Article 87(2) might bear some importance. Judge Treves, in ISA Technical Study No. 24, raised that it “might be read as containing a preference for activities in the Area over the exercise of the freedoms of the high seas” (p. 17). Indeed, as a negative right, freedom of navigation, including for protesting, does not constitute a license to interfere with the exercise of positive rights concerning activities in the Area. 

Nevertheless, both Greenpeace (p. 5) and the Netherlands (para. 12) considered “protest at sea” as a positive right to be balanced against positive rights concerning activities in the Area. While the balance advanced by the Netherlands and Greenpeace is probably correct in the context of human rights law (Amsterdam District Court, paras. 4.7-9) it is not accurate in the law of the sea. Following the Arctic Sunrise award, “the [human] right to protest at sea is necessarily exercised in conjunction with the freedom of navigation” (para. 227). In other words, in the law of the sea, the human right to protest is not directly balanced against NORI’s rights. What is actually relevant is the Dutch freedom of navigation, which cannot interfere with a positive right concerning the Area. 

Undue Interference with the Exercise of Rights

According to the Arctic Sunrise award, “the coastal State should tolerate some level of nuisance through civilian protest as long as it does not amount to an ‘interference with the exercise of its sovereign rights’” (para. 328). One might raise that here the relevance of this award is limited because it deals with sovereign rights in the exclusive economic zone (EEZ), not with rights concerning activities in the Area. In response, to keep it short, one can argue that in practice those rights are very similar (e.g., exploration and exploitation of natural resources) and, in the present case, the Netherlands cited this precise passage in the award (para. 12).

The tribunal considered that it would be “reasonable for a coastal State to act to prevent… dangerous situations that can result in injuries to persons and damage to equipment and installations… and delay or interruption in essential operations” (para. 327). If one follows this precedent, it is beyond dispute that, in the MV Coco events, there was an “interference with the exercise” of the rights of NORI. Regarding dangerous situations, the Dutch investigation concluded that “the presence of Greenpeace activists in kayaks at the stern of the MV Coco created safety hazards towards these persons” (p. 2). As to “delay or interruption in essential operations,” the delay of NORI’s operations was the very goal of the protest (p. 2). 

Here it is fundamental to underscore that, although the law of the sea is “ship-based,” elements internal to the relevant ships might become relevant. For example, under UNCLOS Article 101(a)(1), a ship might be considered a pirate ship, thus not entitled to freedom of navigation, if its crew engages in depredation of property onboard another ship. As such, although Greenpeace actions in the vicinity of or onboard MV Coco fall within Danish or Dutch jurisdictions, these facts are relevant from the perspective of the international law of the sea as well, to assess whether there was “interference” with the rights of NORI.

Finally, it is fair to address the 2010 Resolution MSC.303(87) (“Assuring safety during demonstrations, protests or confrontations on the high seas”) of the International Maritime Organization (IMO). Apparently, by claiming to have conformed to this Resolution, Greenpeace (p. 6) implied that its actions were tolerable nuisances, to use the language of the Arctic Sunrise award (para. 328). 

But the relevance of this resolution is limited. It focuses solely on the safety of navigation and of life at sea, including property and the marine environment. As such, it does not address “rights with respect to activities in the Area.” Furthermore, the Resolution does not cover unauthorized boarding and activities on board the ship at the receiving end of the protest, which interfere with such rights. 

International Responsibility of the Netherlands

The Netherlands, as the flag State, had the due diligence obligation to ensure that Dutch ships do not interfere with the rights of NORI, as per UNCLOS Articles 87(2) and 94(1). The fact that the Arctic Sunrise interfered with the rights of NORI in itself, however, does not make the Netherlands internationally responsible.

Due diligence obligations have been the object of two advisory opinions rendered by the International Tribunal for the Law of the Sea (ITLOS, Cases No. 17, No. 21). I will not delve into all the relevant legal considerations but will point to a few facts that potentially demonstrate that the Netherlands has not taken all the necessary measures to prevent Dutch ships from interfering with rights concerning activities in the Area, particularly the Arctic Sunrise.

On 18 December, Nauru reported the events to the Netherlands under UNCLOS Article 94(6), since it believed that the flag State had not properly exercised jurisdiction and control over the Arctic Sunrise. Under this provision, the Netherlands has the obligation to “investigate the matter and, if appropriate, take any action necessary to remedy the situation.” It conducted the investigation and has been taking action to remedy the situation, i.e., discussing with Greenpeace about “the presence of the Greenpeace activists in kayaks at the stern of the MV Coco [, which] created safety hazards towards these activists” (paras. 16, 18).

However, the investigation concentrated solely on “compliance with the applicable International Regulations for Preventing Collisions at Sea (COLREGs) and the observance of good seamanship” (para. 3) It did not cover the interference with the rights of NORI, even though, according to the Netherlands, “Nauru s[ought], amongst others, ‘an immediate investigation by the Netherlands of the conduct of the MV Arctic Sunrise’” (p. 7). I understand that the Dutch investigation and measures should have included a section on the alleged interference with the rights of NORI. 

As explained above, if one follows the Arctic Sunrise arbitral award, the Arctic Sunrise interfered with the rights of NORI. By not investigating this matter after a report from Nauru under UNCLOS Article 94(6), the Netherlands arguably breached its due diligence obligation under Article 87(2) read together with Article 94(1).

As a caveat to this proposition, it is important to highlight the issue before the Amsterdam District Court, after NORI filed an injunction on 27 November 2023. On 30 November, the Court issued an order for Greenpeace activists to disembark the MV Coco and observe COLREGS (paras. 4.9, 4.13), clearly limiting the right to protest. However, the Court’s reasoning relied primarily on human rights law. The only law of the sea bit was raised by NORI, and it surprisingly concerned the freedom of scientific research in UNCLOS Article 87(1) (para. 3.2), which does not include the right to explore resources in the Area. 


The MV Coco events presented a complex legal landscape. I superficially addressed here only one of its aspects, and the take-home message is that, in the law of the sea, the “freedom to protest” is a negative right of the flag State. It cannot enter into conflict with rights “with respect to activities in the Area.” Although some level of nuisance is tolerable, protests at sea cannot interfere with these rights.

The precise facts of the MV Coco events points towards a possible international responsibility of the Netherlands, as the flag State of the MV Arctic Sunrise, for the failure to comply with its due diligence obligation to ensure that Dutch ships do not interfere with rights concerning activities in the Area, under UNCLOS Articles 87(2) and 94(1). 

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Europe, Featured, General, Law of the Sea, Public International Law
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Arron Honniball

Congratulation Eduardo, a very interesting post and discussion!
A colleague and I have some shared and different views in a post pending on another blog, so would be good to discuss further at next occasion. However, for now I was wondering if you could elaborate a bit on the basis for what appears to be a prioritisation of Activities in the Area over the exercise of high seas freedoms? Due regard obligations are normally reciprocal, acting in a balancing act manner, and I believe this comes out much stronger in Article 147(1) and 147(3) than is apparent in Article 87(2) alone. Would Article 147 affect the negative/positive contrast proposed?