Nautilus calls for UK government to defend international maritime law after vessels seized in international waters

Nautilus is urging the UK government to act following the recent interception of the Global Sumud Flotilla in international waters.

The Flotilla is a civil society‑led international maritime initiative launched in mid‑2025, with the goal of delivering humanitarian aid to Gaza, and pushing for the creation of a humanitarian corridor. Before it was intercepted, it was made up of more than 40 civilian vessels, including a UK-flagged vessel, and roughly 500 activists from more than 40 countries including the UK.

In a letter to foreign secretary Yvette Cooper, Nautilus general secretary Mark Dickinson wrote:

‘This interception by Israeli naval forces constitutes a grave violation of international maritime law, and specifically of the United Nations Convention on the Law of the Sea (UNCLOS) 1982, to which the United Kingdom is a party.

‘Under Article 87(1) of UNCLOS, the high seas are open to all states, and this freedom includes, among others, the freedom of navigation and the freedom of peaceful passage… The Israeli interception of these vessels violates these protections, amounting to an unlawful use of force and an infringement upon the rights of flag states and seafarers and other individuals under international law. This interference with the peaceful navigation of civilian vessels sets a dangerous precedent and undermines the legal framework that governs global maritime conduct.

Mr Dickinson has asked Ms Cooper to publicly condemn Israel’s actions as a breach international maritime law; demand full accountability and the release of any detained seafarers and other civilians; assert the UK’s support for the universal rights, international protection of seafarers and of peaceful navigation and humanitarian engagement; and raise the matter urgently with her counterparts in Israel and at international forums, including the United Nations, International Maritime Organization and the International Labour Organization.

‘I urge you to act swiftly to defend the integrity of international maritime law and the fundamental rights of seafarers and other civilians engaged in peaceful solidarity and humanitarian missions,’ he said.

The European Transport Workers’ Federation (ETF), of which Nautilus is a member, has now adopted a resolution on the same subject. Under this resolution, the Maritime Transport Section of the ETF condemns the unlawful interception of the Global Sumud Flotilla and the detention of its crew and passengers in international waters; demands the immediate and unconditional release of all detained seafarers and humanitarian volunteers and their safe repatriation to their home countries; and calls for national and international bodies to investigate the incident.

It also urges the International Maritime Organization to reaffirm the inviolability of the freedom of navigation and to defend the safety of civilian maritime operations, requests the International Labour Organization (ILO) to monitor the treatment of detained maritime workers in accordance with the Maritime Labour Convention.