A British sailor says a gaggle of killer whales gave the impression to be attempting to chunk her yacht aside as they rammed it for over an hour off the coast of Spain.

A video shared on social media by April Boyes, 31, reveals the group of orcas closing in on the yacht earlier than slamming into it repeatedly.

Screams of terror might be heard from the four-person crew because the orcas destroy the rudder and pierce the hull, forcing these on board to bail out incoming water as they concern frantic mayday requires assist.

The assault is considered one of a rising quantity by orcas round Gibraltar and it's believed that one feminine killer whale, traumatised by an encounter with a ship, has been coaching others to prey on them.

"It's like they are biting it apart," Ms Boyes says within the video posted on her Instagram web page .

Read extra: Inquiry into killer whale attacks off Spain

A determined male crew member might be heard calling for assistance on the radio, saying: "We need assistance immediately, we are sinking, we are sinking." Another is seen battling to empty the rising water from the yacht's engine room.

A Spanish rescue boat and a helicopter lastly got here to the help of the 66ft British-registered vessel and it was towed to the port of Barbate, Cadiz, for repairs.

Ms Boyes mentioned: "What started off as a seemingly unique encounter ended with orcas breaking off our rudder from the boat, then proceeding to tear bits off the boat for an hour.

"An enormous gap within the hull meant we had water ingress to different elements of the boat and the engine room and I can truthfully say it was a scary expertise. We are all secure, I'm feeling grateful for the coastguard."

There have been at least 20 orca attacks on small vessels off Gibraltar this month alone.

This week it emerged that a female killer whale called White Gladis may have taught other orcas to attack vessels.

Scientists think an incident in which White Gladis may have collided with a vessel or was caught in illegal fishing nets led to her aggression.

On May 2, around six orcas reportedly rammed the hull of a Bavaria 46 cruiser yacht on the Strait of Gibraltar.

Janet Morris and Stephen Bidwell, both 58, from Cambridge, were on the yacht. Mr Bidwell told The Daily Telegraph: "A clearly bigger matriarch was positively round and was nearly supervising."

Alfredo López Fernandez, an orca researcher at the Atlantic Orca Working Group, told livescience.com: "The orcas are doing this on objective.

"Of course, we don’t know the origin or the motivation, but defensive behavior based on trauma, as the origin of all this, gains more strength for us every day."