In August 2026, an unusual gathering of at least 500 hammerhead sharks was spotted in shallow waters near the island of Ré, a popular surfing destination. The event was first noticed by surfers near Portes-en-Ré, who alerted photographer and sailing professor Gaël Contal. Investigating the sighting, Contal encountered a large number of sharks in the water, estimating that if he saw one, it was already significant, but the actual number was "really crazy." Using a drone, he captured aerial images of the sharks, which were later analyzed by the Association for the Study and Conservation of Elasmobranchs (Apecs). Marine biologist Éric Stéphan, coordinator of the association, estimated at least 500 individuals based on the images, though this remains an estimate from a single photographer and not a comprehensive census. The sharks remained in the area for five days, moving along a 500-meter strip along the coast and 100 meters out to sea, sometimes in water so shallow that their backs surfaced. The sharks measured between 1 and 2 meters and were described as relatively harmless to humans. Witnesses, including surfers and lifeguards, confirmed the phenomenon, though the cause remains unclear. This event is not isolated, as a similar occurrence was reported the previous summer at beaches in Lizay and Grand-Marchais, and an older incident involved a group of sharks stuck in a fish lock in Sainte-Marie-de-Ré. Apecs, which has been conducting a tagging program since 2018, noted that such a gathering had never been observed or reported in French waters. The hammerhead shark, classified as critically endangered worldwide by the IUCN in 2020 and vulnerable in Europe and the Mediterranean, is protected under international agreements. The species is considered extremely vulnerable due to late sexual maturity and low fertility, making population recovery difficult. Scientists lack sufficient visual data on the species, relying largely on tagging programs. Three hypotheses have been proposed to explain the gathering: feeding, reproduction, or the tranquility of the location. The feeding hypothesis is less convincing, as hammerhead sharks are not typically known for living in groups. The reproductive hypothesis is possible, though the sex ratio of the group is unknown. The tranquility of the location is a more grounded hypothesis, as the beach had been inaccessible for 15 days due to fire risk, potentially reducing human activity. The sharks eventually dispersed as discreetly as they had appeared. Apecs plans to study the waters of Charente-Maritime more closely in the coming months and encourages the public to report shark sightings through its online form.