Following a report from a foreign intelligence agency that the sailing boat Vague à l'Âme would transport a large quantity of cocaine from Ecuador to Australia, the French military authorities carried out surveillance of this boat on 9 February 2016 and noted suspicious behaviour. On 13 February 2016, the French navy frigate Prairial intercepted the boat sailing without a flag in the international waters of the Pacific Ocean off the Gambiers archipelago of French Polynesia. At 04h05, one of the crew members, who had not answered VHF calls from the French soldiers, appeared at the rear of the boat and deployed a Panamanian flag. The soldiers boarded the boat at 4h20 am with the authorisation of the captain, and discovered two other crew members. They carried out an investigation which revealed the absence of any logbook or navigation log. At 07h42, after having collected the identification elements of the boat, the soldiers remained on board, on the instructions of their superiors and with the agreement of the master, pending a response from Panamanian authorities to a request for authorisation to visit the boat. At 16h42, after the authorisation to visit was notified to him, the captain of the sailboat spontaneously admitted that he was carrying cocaine and showed the soldiers where some 30 bundles were stored, which turned out to contain 733 kgs of this product.

The accused appealed on the ground that arts 95, 96 and 110 of UNCLOS had been violated. They argued that it followed from art 110 of UNCLOS that, except in the case where the intervention proceeds from powers conferred by treaty, a warship which encounters a foreign ship on the high seas, other than a vessel enjoying the immunity provided for in arts 95 and 96 of the Convention, may board it only if it has serious grounds for suspecting that this vessel is without nationality. The nationality of a vessel is established by its flag. It follows that at 04h05, concomitantly with the boarding, the Panamanian flag of the vessel was identified and its nationality established. By nevertheless deeming this to be a regular flag investigation, the investigating Chamber violated art 110 of UNCLOS.

Held: Appeal dismissed.

There is no need to annul the documents relating to the flag investigation carried out on the basis of art 110 of UNCLOS. The judgment states that the fact that the captain of the boat waved a Panamanian flag when he had not answered the VHF interrogations of the officers of the national navy, not allowing the latter to ensure the nationality of the vessel, a flag investigation was justified. The judgment adds that the captain of the sailboat accepted, at the request of the French soldiers, that they board his boat to facilitate the examination of documents under optimal conditions of safety.

It follows that, notwithstanding the ad hoc and late exhibition of the Panamanian flag, and taking into account the lack of response from the members of the crew to the calls of the French soldiers, suspicions regarding the nationality of the boarded vessel were likely to remain within the meaning of art 110 of UNCLOS, justifying the continuation of the flag investigation and the control of navigation documents. The Court of Appeal justified its decision.