Orcas, or killer whales, are well known for their intelligence and for their remarkable hunting techniques: whether it’s turning great white sharks upside down or working cooperatively to take down large whales. And a population of orcas off the Iberian Peninsula has been gaining attention over the last three years—and causing angst among sailors—by attacking and even sinking boats in the area.

The first recorded attack occurred in the Strait of Gibraltar in May 2020, with dozens of cases recorded since then. Most of the incidents are remarkably consistent, generally involving a small group of whales attacking the rudders of small sailboats before breaking off and swimming away.

In June and November