What damage can an orca “attack” cause?

The sea can always surprise us with unexpected situations that would not even cross our minds before casting off. Before setting sail, all sailors gain knowledge of the possible adverse circumstances that they may encounter on their voyage, preparing themselves and their yachts for the difficult situations that they believe could occur during their navigation. Normally one tends to think about the wind, the sea, the other boats, the storms, possible failures or breakdowns…

Photo Credit: Martin Evans @hellpants


But lately, incidents with marine fauna are occurring and they seem to be becoming more frequent. Something that years ago did not even cross our minds. Moreover, when there were sightings of marine animals, whether they were dolphins, whales, sperm whales, turtles, seals or any other form of life in the sea, it was viewed as a moment of beauty, joy, and pleasure. It is obvious that it will continue to be so. But the behaviour that the orcas are having lately in certain waters with repeated “attacks” on boats, especially medium-sized sailboats, is generating concern among all those sailors who are going to sail in those areas, the questions would be: Why is this happening? What damage can my yacht and my crew suffer? How can I avoid or prevent it?


The “why” may be the most difficult question to answer. Perhaps the almost exponential increase in sailboat attacks in recent years is due to the significant increase in noise pollution in frequencies used by us and by these animals; the scarcity of fish in the sea; our interference in their hunting territory; our behaviour towards them. It’s unfortunately not known …perhaps it’s one of the reasons above, a combination of them, or something we haven’t even thought of yet… It’s simply not yet known.

There are a multitude of conjectures, theories, and, of course, opinions. It would be too extensive to expound on all the different “versions” that exist. It really is more appropriate to leave it to scientists to discover the reason for this behaviour.

What we can focus on, given the numerous experiences lived and recorded by sailors who have suffered such “attacks”, is the extent of the damage suffered by the boats. Some boats suffered major damage and others, with perhaps greater luck, only minor damage. Proper reporting of these events is of critical importance to scientists who are working on discovering the root cause of this behaviour. Personally, on the numerous occasions that I have met these animals, they have always respected me. I have followed my course, doing nothing more than observing them and appreciating their beauty and elegance – that has not been the case for all….


What does seem to be a common denominator is the area of the boat that usually gets “attacked”, they usually focus on the rudder blades, whether there are one or two. It seems that, for whatever reason, they are attracted to them and it is clear that, as it is the steering system, losing it can lead to delicate situations where the boat cannot be steered and remains adrift. Additionally, it opens possible ways for water ingress in the wheelhouse and its surroundings, depending on the design of the rudder stock and how each specific boat is structured. Fortunately, this area is typically one of the most solid regions of the boat. The damages usually are total or partial loss of the rudders, which can be a very dangerous circumstance if it happens near the coast or in areas with a lot of boat traffic and/or strong currents, such as the Strait of Gibraltar. The most reported orca interactions have been along the coast of Cadiz, Portugal, and Galicia. These situations have occurred both during the day and at night, according to the testimonies of the yachts that have been involved.

Given that these animals can reach 9 meters in length, 5 tons in weight, and move at speeds of 30 knots, you must clearly feel great anguish when you see a killer whale “playing” with your boat, also considering that it is unpredictable to know how much damage it might cause. It must not be a pleasant situation and must generate a significant degree of fear…

Photo Credit: Pete Green Halcyon Yachts


Many sailors must wonder how to avoid or prevent it from happening. As in the case of “why”, there are also many theories. Some yachts that have found themselves in that situation have made certain manoeuvres that seem to have had positive results. The one manoeuvre that has been posted quite a bit lately in pages like “Orca attack reporting” is to put the boat in reverse and go back in circles, provided that sea and wind conditions allow it. There is also information about the use of “Pingers”, which are normally used in certain fishing nets to prevent dolphins or cetaceans from getting entangled in them. There are many opinions about what to do or not to do and what is right or wrong, while not knowing if it will work or not. However, the authorities recommend lowering the sails, stopping the engine, disconnecting sound-producing probes, letting the rudder to be free, staying out of sight not near the edge of the boat, not throwing anything at them, or reprimanding them or trying to move them away from the boat with gaffs, harpoons or any other object.

In the case of the Imoca, for example, studies and tests have been carried out on two systems more focused on avoiding colliding with whales, cetaceans, or unidentified floating objects (OFNI) than to prevent an “attack” by killer whales. One of them is known as the “WHALE SHIELD”. It is basically the installation of a “Pinger” in the front part of the bulb at a depth of 4.50 meters, which emits frequencies that are supposed to keep the cetaceans away.

“Pingers” are emitters of frequencies with emissions of less than 150 db in the medium to high range (from 2.5 to 109 khz) and with much higher harmonics underwater. Cetaceans experience pain (depending on the species, age, and health status) when they exceed 20 khz and have a repulsive effect between 30 and 160 khz.


Another system that was tested on the Imocas is “OSCAR” (Optical System for Cognition and Range), which is already available on the nautical market. It is the first system assisted by artificial intelligence and warns of floating objects on our course, both during the day and at night. Using thermal and optical cameras, it warns of objects that can not be “seen” on radar or sonar.

All these tests were carried out more for the sake of avoiding collisions at sea than to repel interactions with orcas, however, “Pingers” could be one of the “solutions” to this problem.

In events such as the Global Solo Challenge (GSC), the participants will only go through “hot” zones of orca “attacks” at the beginning and at the end of their course, along the Galician and Portuguese coasts. Perhaps, in a route around the world, the problem of collisions with “OFNI” is more relevant than orca “attacks”, however, the use of both systems could be of help.

Foresight, information, good seamanship, material, and spare parts to make repairs on board, be able to make a functional rudder, repair small leaks, and carry out many other emergency manoeuvre is something that we should be able to do and know how to do regardless of possible orca “attacks”.

Photo Credit: Pete Green Halcyon Yachts