In a First, Orcas Stalk Boat to Port

It's still unclear why a group of orcas is attacking the rudders of sailboats off the Iberian Peninsula. What is clear is that they're not letting up. There were 20 incidents in the Strait of Gibraltar in the month of May, per the Independent. And in one case, the killer whales stalked a boat all the way to shore after they'd completely destroyed its rudder, per Live Science. This marks a change as, in past incidents, the whales would lose interest and swim away once the rudder was disabled. In the May 24 case, a pod of orcas began striking the rudder of the Mustique soon after finding the vessel in the strait around 9:30pm local time. "The force of this would spin the helm violently and you could feel the vibration through the deck," British sailor April Boyes writes in a blog post.

She and her three fellow sailors tried using deterrents, including sprinkling sand in the water, which is meant to disrupt the orcas' sonar. But the strategies didn't work. "After around 30 minutes the rudder was now broken, but some of the orcas swam away," Boyes writes. However, they returned within 20 minutes and continued striking the rudder for another hour until it was "completely destroyed," leaving "a gaping hole ... with seawater flushing in," according to Boyes. Unbeknownst to the sailors, the hull had also "cracked through the fiberglass." It was enough for a mayday call. But the orcas weren't deterred by the rescue boat, which towed the Mustique to Barbate. As Boyes writes, "the orcas continued to follow the boat until we got inshore."

Boyes calls for "extensive research" into the issue, noting that "demonizing [the orcas] is not the answer." Another British sailor who recently watched orcas rip both rudders from his yacht in the Strait of Gibraltar tells the BBC that they "seemed to be playing" and could've easily destroyed the vessel if they wanted to, per Insider. Experts from Conservation, Information, and Research on Cetaceans (CIRCE) have already tagged one orca involved in attacks and plan to do the same with five more so as to track their movements, per Live Science. But biologist Alfredo Lopez Fernandez, who's studied the interactions, fears this will only "aggravate the situation because it is done by shooting and the killer whales will surely not find it very funny," per the outlet. (More orca stories.)