The local maritime rescue service said on Thursday that killer whales seriously destroyed a sailing boat off the southern Spanish coast, adding to the scores of orca assaults on vessels that have been documented so far this year on the Spanish and Portuguese coasts.

The Mustique’s crew of four called Spanish authorities for assistance in the early hours of Thursday after a pod of orcas rammed into it as it was sailing toward Gibraltar, according to a spokesman for the maritime rescue agency. The orcas destroyed the rudder and punctured the hull.

The service deployed a rapid-response vessel and a helicopter carrying a bilge pump to assist the 20-metre (66 feet) vessel, which was sailing under a British flag, he added. The Mustique was towed to the port of Barbate, in the province of Cadiz, for repairs.

According to the research group GTOA, which tracks populations of the Iberian orca sub-species, the incident follows at least 20 interactions this month alone in the Strait of Gibraltar between small vessels and the highly social apex predators. In 2022, there were 207 reported interactions, GTOA data showed.

Earlier in May, the sailing yacht Alboran Champagne suffered a similar impact from three orcas half a nautical mile off Barbate. The ship could not be towed as it was completely flooded and was left adrift to sink.

Guidelines issued by the Spanish Transport Ministry stipulate that whenever ships observe any alteration in the behaviour of orcas – such as sudden changes of direction or speed – they should leave the area as soon as possible and avoid further disturbance to the animals during the manoeuvres.

Every interaction between a ship and an orca must be reported to authorities, the ministry added.

Although known as killer whales, endangered orcas are part of the dolphin family. They can measure up to eight metres and weigh up to six tonnes as adults.