After a brief hiatus, it looks like the boat-attacking orcas of the Mediterranean are back. Two sailors had to be rescued this weekend after their boat was reportedly struck by a group of orcas in the Strait of Gibraltar.

The sailboat, named Alborán Cognac, encountered the feisty cetaceans on the morning of Sunday, May 12, around 25.9 kilometers (14 nautical miles) from Cape Spartel in Morrocan waters, according to Spanish newspaper El País.

The crewmembers said their 15-meter (49-foot) boat was rocked by several blows to its hull, after which they noticed damage to the rudder and water leaking into the vessel. The Spanish maritime rescue service was alerted, and a helicopter was mobilized and a passing oil tanker was requested to assist with the recovery. 

The pair were rescued by the nearby MT Lascaux oil tanker before their boat slowly drifted and sunk.

Since May 2020, hundreds of similar orca attacks have been seen in the Mediterranean around the Iberian Peninsula. According to the Atlantic Orca Working Group, at least 52 disruptive interactions were reported between July and November 2020. In 2021, a total of 197 interactions were clocked, while 207 interactions were recorded in 2022. 

Orca, also known as killer whales, are a highly intelligent, socially complex species of toothed whale. Although they are apex predators of the ocean, they are typically peaceful when interacting with humans in the wild. 

The species has a cosmopolitan distribution, meaning they are found in waters across the world, but there's a small population that lives year-round in the Strait of Gibraltar.

Researchers are unsure why this new behavior has emerged in the Strait of Gibraltar, although it does have to have spread through social learning – a testament to the fierce intelligence of these animals. 

Some orca experts believe the behavior may be playful, while others suggest it may be a more aggressive strategy to obtain food. Perhaps they’ve associated vessels with fishing and the snatching of much-needed tuna, others have pondered. 

While it does appear the number of orca attacks has significantly dropped in 2024 so far, researchers are keen to better understand this curious – and potentially worrying – novel behavior. 

“If this situation continues or intensifies, it could become a real concern for the mariner's safety and a conservation issue for this endangered subpopulation of killer whales,” explains a 2022 study on the orca attacks.

“There is an urgent need to conduct dedicated research that would help better understand the behavior of the animals and implement mitigation measures,” they conclude.