British sailor describes 'terrifying' moment group of killer whales sunk his £100k boat in 'violent attack'

A British sailor has described the horrifying moment his yacht was violently targeted by a group of killer whales.

Reports of killer whale - also known as orcas - attacks on boats off the coast of Spain and Portugal have been increasing over the past couple of years, leaving many marine biologists baffled by the new concerning trend.

One of the latest victims of this terrifying new killer whale trend is 59-year-old Robert Powell, who was left feeling like a 'sitting duck' during a two-hour orca attack in the Mediterranean Sea.

Robert Powell had been sailing from Portugal to Greece to celebrate his 60th birthday. (SWNS)

Powell was just 22 hours into a 10 day trip from Vilamoura, Portugal, to Greece to celebrate his 60th birthday when the animals began their sustained attack.

Powell explained how a group of five orcas had begun to circle his boat like a pack of 'wolves' before taking turns smashing into the vessel.

The sea creatures will often hunt down the vessels in groups, before attacking by ramming and biting the underside of the boat until it capsizes.

Recalling the moment he realised the boat was under attack, he said: "All of a sudden I felt something really hard hit the bottom of the boat. My initial reaction was that I'd hit a rock or fishing net or I'd hit something submerged... Whilst I was looking around the boat to see if I could see anything it got hit again."

They travel in packs. (Serge MELESAN / 500px / Getty Images)

"On the second hit, I looked over the back of the boat and I could see the dark shape of a killer whale in the water."

After successfully taking out the boat's rudder, Powell was left feeling powerless as two more orcas joined the existing group of three.

He added: "Once the rudder was disabled, all five orcas circled the boat. And one by one they kept coming in and ramming in various different places."

The IT company owner went on to explain that the most terrifying part of the attack is its violent and intentional nature, saying: "It was really the violence of the attack that surprised me. To me they were not playing at all, they knew exactly what they were doing.

"They knew the weak points of the boat and they knew how to sink it. Their sole intention was to sink the boat, and that was it."

The horrifying attack had lasted for two hours. (SWNS)

The 59-year-old explained that he had tried various techniques to stop the killer whales from attacking the boat - none of which had worked.

Powell then inflated life rafts and made plans to exit the vessel with the two other members of crew, before attracting the attention of a nearby Spanish salvage vessel.

Around 15 minutes later, the boat would sink to the bottom of the sea. "And that was the end of that," Powell added.

Under current laws, sailors are not allowed to shoot or throw things at the killer whales. However, Powell thinks it's only a matter of time before things change.

"It's only a matter of time before someone shoots one of these killer whales," he said.

"The fight between man and beast is going to get worse."