The Mysterious and Dangerous Behavior of Killer Whales Towards Boats.

A pod of killer whales bumped one of the boats in an endurance sailing race as it approached the Strait of Gibraltar, the latest encounter in what researchers say is a growing trend of sometimes-aggressive interactions with Iberian orcas. Scientists have noted increasing reports of orcas, which average from 16-21 feet (5-6½ meters) and weigh more than 8,000 pounds (3,600 kilograms), bumping or damaging boats off the western coast of the Iberian Peninsula in the past four years. The behavior defies easy explanation.