Marine biologists say evidence suggests that orca interactions with yachts are ‘playful’ rather than aggressive, but at risk of becoming ‘learned behaviour’.

It comes after a French-flagged Oceanis 393, with four crew on board, sank following an ingress of water caused by orcas pulling off the rudder, 14 miles west of Viana do Castelo, Portugal.

The Mayday call was made at 1205 on 1 November, and Lisbon Maritime Search and Rescue Co-ordination Center (MRCC Lisboa) tasked the Viana do Castelo Lifeguard Station crew to the scene.

Upon arrival, it was found that the sailors had been rescued from a liferaft by a nearby cruiser, they did not need medical assistance. The stricken vessel later sank, and the lifeboat crew collected pieces of wreckage.

No source of pollution was detected at the site.

Oceanis 393 sinks off Portugal after orcas pulled off the rudder. Credit: Augustin Drion

Oceanis 393 sinks off Portugal after orcas pulled off the rudder. Credit: Augustin Drion

French sailor and marine biologist, Augustin Drion, 29, who was among those rescued, told PBO he believed the orcas will be ‘learning’ through these episodes.

He would not call them ‘attacks.’

“They could be playing, they did not seem to be aggressive, they can weigh up to 6 tons, if they wanted to be aggressive they would only have to jump on the boat and that’s it”, he said.

“But they are just so huge, that even playing can be a disaster.”

Orca behaviour studies

This theory is supported by Alfredo López, of the Grupo Trabajo Orca Atlantica (GTOA) which is studying orca interactions with yachts in collaboration with the Cruising Association (CA).

He said: “Indeed, we do not interpret the behaviour of killer whales when interacting with boats as aggressive.

“We do not have enough information about the latest incidents that resulted in the sinking of a yacht on 1 November.

“A leak can occur if the rudder does not break or bend and the rigid structure presses on the entry area in the hull. It doesn’t have to be a special interaction.

“The photos of the interactions are always scarce and of very poor quality, people do not have good cameras and are busy with other things.”

López added: “The action protocol was designed to reduce the orcas’ motivation, since speed increases their arousal.

“Stopping the ship and then slowly backing away, if the sea allows it, reduces the time and intensity of the interactions but does not completely eliminate them.”

An orca interacting with a yacht. Credit: Grupo de trabajo Orca Atlántica (GTOA)

An orca interacting with a yacht. Credit: Grupo de trabajo Orca Atlántica (GTOA)

Common trends

An International Whaling Commission report in May 2022 entitled ‘Update on the interactions between killer whales and vessel along the Iberian Peninsula’, looked at 253 interactions between killer whales and vessels, mainly along the Atlantic coast of the Iberian Peninsula.

It identified 14 individual orcas, mostly juveniles, distributed in up to four interacting groups.

The report found: “Most of the vessels involved in interactions are less than 15m sailboats, with spade rudder, sailing at an average of 6 knots, both under sail and motor. Interactions occur throughout the year, although they are mostly concentrated in the summer and autumn.”

Interactions occurred at all times but were concentrated in the midday hours, lasting an average of 35 minutes.

The report said: “The behaviour when interacting with boats was not identified as aggressive.

“No clear motivation has been found for this new behaviour; however it seems like a curious and playful behaviour, which could be self-induced, or induced by an aversive incident.”

Russell Leaper, a whale specialist from the International Fund for Animal Welfare, said: “We do know killer whales are very good at learning new behaviours and these are often adopted by other members of their group.

“This is usually food related but there have been previous reports of groups of killer whales adopting unusual behaviours such as playing with salmon rather than eating them.

“The Strait of Gibraltar population is subject to a huge amount of commercial and recreational boat traffic which does make their lives very difficult, particularly due to underwater noise levels.

“It may be that excessive disturbance has caused these unusual behaviours.

“Underwater noise has been identified as a serious threat to other killer whale populations, and in Canada the Port of Vancouver has initiated a voluntary slow down programme for large ships approaching the port in an attempt to reduce the noise impacts on the killer whales.”

What happened?

It was French sailor Augustin Drion’s first time sailing off the Portuguese coast.

He was helping a friend to sail The Smousse, an Oceanis 393, across the gulf when six orcas appeared suddenly.

Drion told PBO that they managed to stay calm, they had practised emergency drills and read orca advice, knowing to turn everything off on the boat, and not react. One orca took hold of the rudder in its mouth and was “trying to shake it”.

As the Portugal Resident newspaper described, The Smousse had become ‘a plaything of the orcas’; when one stopped shaking it, another took over.

Drion said: “We did not radio for help at first. We believed it would be over, and we would be able to assess damage.”

But then they heard ‘the cracking’. A hole appeared at the stern, and water poured in.

A Swedish yacht responded to their Mayday call, saying they were less than an hour away.

The orcas “finally got the rudder and left with it” just before the crew had to abandon the sinking vessel for a liferaft.

Drion said: “I don’t want to imagine what could have happened if we’d had to get in the liferaft surrounded by six orcas.”

Familiarising themselves with safety equipment prior to departure proved to be invaluable:

“We had 20-30 minutes to leave the boat, you haven’t the time to read the notice on the rescue devices. Being prepared helped us to stay calm and to react as well as we could.”

French sailor and marine biologist,

Augustin Drion

Augustin said he had since been advised that “avoiding the use of sonars” and “shutting down all electronic devices” could have helped.

He added: “They didn’t seem aggressive, it was exactly as when you’re surrounded by dolphins and they play with the boat and swim around.

“It was in the middle of the day, most fish and sea mammals tend to feed during the night or early morning, that’s something that could confirm this theory that they were being playful.

“For me, there are some key issues this incident raised, that sailors must be aware of.

“Firstly how to avoid these kind of interactions – this could be GPS tracking, more exchange between sailors about where they last saw them and what time. Maybe the Portuguese and Spanish authorities can publish some maps of where they were last seem.

“Secondly, which response to give when you’re faced with this kind of interaction. Some people suggest throwing sand, which may disrupt the sonar of the mammals and may make them go away.

“As sailors we have to be aware of the weather and conditions, that’s part of the game, not trying to change what’s on and in the sea, it’s thinking about how we can react to it.

“To me, the idea that we respond with aggression is a really bad idea, we can not anticipate how the orcas would react when they feel attacked, particularly if there was a mother and young.

“I’m pretty sure all the sailors have this sense of respect for the ocean and what’s in it.”

An orca interacting with a yacht. Credit: Grupo de trabajo Orca Atlántica (GTOA)

An orca interacting
with a yacht. Credit: Grupo de trabajo Orca Atlántica (GTOA)

Advice to sailors – what to do if orcas interact with your boat

An orca interacting with a yacht. Credit: Grupo de trabajo Orca Atlántica (GTOA)

An orca interacting with a yacht. Credit: Grupo de trabajo Orca Atlántica (GTOA)

  • Disconnect autopilot to avoid damage and let the wheel/tiller run free. Keep hands off wheel or tiller to avoid injury
  • Stop the boat, de-power and drop/furl sails
  • In conditions that make it safe to do so attempt to go slowly in reverse
  • Contact the authorities on VHF Ch16 or by phone on 112
  • Keep a low profile on deck to minimise the interest to the orcas
  • Keep a firm hold when moving around to prevent injury in the event of ramming
  • Take photographic or video evidence while keeping a low profile. Make a note of location co-ordinates and timing of the interaction along with any other relevant details including the behaviour of the orcas for future reporting
  • After the interaction ceases, wait for several minutes to allow the orcas to move away from the area so as not to regain their interest.