In the last three years, orca have started ‘attacking’ yachts on their way through the Gibraltar Straits. James Kenning looks at how to minimise the risk

There is a new buzzword amongst cruisers heading in and out of the Mediterranean through the Straits of Gibraltar… orcas! Wind, tide and shipping are no longer the only planning considerations in making passage through the Straits; it is avoiding an encounter with the family of Iberian orca that have developed a taste for sailing boat rudders.

This issue is largely isolated to this geographical area and the distinct orca population of 50 or so animals that live there. However, shortly before we published this piece, reports came in of a yacht being repeatedly rammed by an orca near the Shetland Islands, over 1,500 miles away.

This remains a one-off at the moment, though over the years there have been a number of reports of orcas interacting physically with yachts. The thing that has alarmed sailors off the Iberian peninsula is the frequency and severity of the interactions in a trend that is very recent.

The first series of interactions between yacht and orca, where the cetaceans make purposeful and damaging contact with boats, were recorded in the post-COVID sailing season of 2020.

Initially it was thought ‘unlucky’ to be the victim of oneof these rogue interactions (or ‘attacks’ depending on your point of view) where the orca would deliberately target the rudder of a transiting sailing boat.

Encountering cetaceans is normally a highlight of a trip, but recent encounters are resulting in damaged boats. Photo: James Kenning

Skippers of affected yachts talked of fear and helplessness as the large mammals spun boats around and literally chewed their rudders to destruction. In 2022, the threatof these interactions became even more serious with two boats suffering damage so severe that the yachts sank, thankfully without loss of life.

In 2023, the number of interactions between orca and yachts has significantly increased and, with the sinking of a third boat in May, the phenomenon briefly became the focus of international news and, in some reporting, sensationalised.

For a sailor’s perspective on the subjective experience of these interactions, Thomas Käsbohrer’s book, The Riddle of the Orcas, is a well-researched collection of 19 stories, from which he speculates on possible causes and solutions.

The author’s boat, Arkyla, on passage, during which he managed to avoid orca interactions. Photo: James Kenning

Planning our passage

Needing to deliver my Regina 43 Arkyla from her Portuguese winter base of Lagos to her new seasonal home of Valencia, minimising the orca risk became my overriding concern in my passage planning along the Algarve, through the Straits, and to the considered safety of Gibraltar and the gateway to the Med.

It became clear that information would be the key weapon for keeping myself, boat and crew safe whilst transiting the danger zone. The issue was now one of clearly identifying the ‘danger zone’ and, with an almost overwhelming array of ‘official’ and ‘expert’ advice to decipher, of deciding what sources of reporting and information to give most credence.

The first point of note is that the area of threat is not a constant; the orcas migrate seasonally from the Straits, up the Portuguese Atlantic coast, and into the Bay of Biscay. However, whilst their location may vary it is, nonetheless, predictable; the orcas travel with a purpose – to follow the tuna they primarily feed upon. And neither is this family of orcas new to science; Dr Renaud Stephanis and a team of researchers from CIRCE (Conservation, Information and Research of Cetaceans) have been studying this group within the Straits for 20 years now and their seasonal migration patterns, as well as the individuals within the family, are well known.

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While there is much research, and speculation, into the causes of this new behaviour, the reasons behind it are not known. From play, to training, to responding to traumatic experiences or competition for food, a range of possible triggers are mooted. The population is categorised into five separate communities, some of which overlap with each other and others which do not.

Orca are matrilineal animals, and much behaviour is learnt from the older post-menopausal females within the group. The website includes a full photographic catalogue of every animal’s unique markings and history, if you are interested in identifying them.

While orca are distributed around the world, this particular population is unique. It was listed as critically endangered by the Spanish government in 2019 and is therefore subject to a range of protections.

An official heat map indicating the high risk areas for orca interactions

The animals are biologically different, most obviously being smaller (around 6m in length), than their orca cousins in the north-east Atlantic, which can grow up to 9m. It is now known that an orca called Gladis Blanca (Gladis being the family name), a grandmother, has demonstrated ‘attacks’ on yachts, and while not thought to be training the younger animals, they have been replicating her behaviour.

Gladis Blanca is known to have experienced and witnessed traumatic experiences, including the wounding, mutilation and death of members of her family group, and it is speculated that this may have been a trigger for the behaviour. Orcas are highly intelligent, social animals, well able to develop, share and copy new behaviours.

Tracking orca behaviour

During April, May and June, the orcas remain within the Straits; through a combination of daily monitoring by boat, and more recently GPS tagging, locations of the ‘problem’ orcas are accurately known. Things become a little less clear as the summer develops, however, when the orcas migrate northward toward Biscay and go ‘out of bounds’ of the Spanish Barbate-based research team.

The GTOA and Cruising Association both collate reports of orca sightings and encounters, the majority of which still do not involve any physical contact with boats. Photo:

For the Straits area, however, location data is our primary defence. Heat maps depicting current danger areas are available from The site encourages sailors to sign up to a set of forums on the Telegram app. ‘Location reports’ is for recording interactions and event-free passages, whilst the wider ‘orca discussions’ forum provides a space to discuss tactics and potential solutions. I would consider membership of both forums essential.

The GTOA and the Cruising Association disseminate data and reports on the nature of these interactions in an attempt to understand both the orca’s behaviour and the measures sailors can take to protect their boats from damage.

Avoiding orca encounters

The key tactic for avoiding the killer whales is clear; keep away from the known orca locations. The advice is to transit the Straits (and indeed the Atlantic coast of Portugal) in shallow waters. If possible, keep within the 20m depth contour where very few interactions have so far been recorded.

This yacht sank in Barbate harbour after it had been towed in following orca damage. Photo: James Kenning

During my passage east in late May, on average one to two boats were towed daily into Barbate by the Salvamento rescue service. Almost without exception, the disabled boats were attacked whilst transiting directly through the known, and published, orca hot spots further offshore.

In particular, the areas off Barbate and, on the African side of the Strait, Tangier, were proven to be the most dangerous for boats on passage.

Inshore hazards

The navigation to stay shallow has its own challenges, of course. The coast is littered with small fishing pots, many poorly marked. Night sailing brings far too great a risk of snagging a prop close to shore, so the safest strategy is to plan a series of day hops along the coast.

Fortunately, there are plenty of well-spaced ports of refuge, so it is only time that becomes the major limitation. I chose to make stops in Ferragudo, Culatra, Mazagón, Rota, and Barbate before my last push through the threat zone to Gibraltar.

The marinas along this stretch of coast are not expensive, so cost is not a prohibitive factor – indeed, the opportunity to explore a little adds some interest to what might otherwise be a ‘dull delivery trip’.

Orcas ‘attacked’ this catamaran while it was being delivered to the Med. Photo: David Smith

Seasonal tuna nets provide another obstacle to safe passage. These are laid off Conil, Barbate, Zahara, and Tarifa. They are charted and well-buoyed but extend into the danger depths where orca may prey.

Some nets can be passed shoreside, but a skipper must make careful consideration of weather and sea state – generally an ‘inside passage’ should only be made in the calmest of conditions. I chose to go inside the Zahara net, where depth below keel bottomed out at 1.3m, but it was the proximity to the shore (perhaps 30m) that made my knees tremble! A friend tracking my progress by AIS later asked if I had trailered on land for that stretch!

The Telegram forums provide a valuable resource regarding the ‘live’ status of the tuna nets. Some nets may be periodically attached to shore making them impassable, and precise descriptions of ‘rogue’ buoys helps when making informed decisions.

The Salvamento rescue boat has been very busy towing orca-damaged boats back to harbour. Photo: James Kenning

Responding to orca attacks

The best defence is to avoid the orcas entirely, but what are the recommended actions if one is unfortunate enough to be subjected to an attack? Here the advice diverges and ‘attack actions’ must be carefully considered.

There are many theories and much discussion around how best to respond should orcas make contact with your boat. Broadly, they are divided into passive and active measures – making noise or remaining silent, stopping or accelerating either forwards or backwards, putting things in the water or avoiding drawing attention. There are also suggestions of more aggressive measures, some of which are illegal in the various territories.

Initially yachts were advised to switch off all electronics, hide below decks, and wait until the orca grew tired of interacting with the boat and left. While this remains the official advice from bodies such as the Cruising Association and GTOA, the statistics now show that most of the measures have very little, if any, effect on the severity or duration of any encounters.

The latest advice is to motor at best speed straight for shallow water. Photo: Graham Snook/YM

Switching off electronics is not now considered to be a helpful tactic but turning off the engine and waiting out the attack remains the official advice from the GTOA. Unfortunately, in most cases, the orca only cease interaction once they have destroyed the rudder as it is only then that they lose interest in the ‘game’. This often leaves the yacht unable to continue and it usually requires a tow to harbour by the rescue services.

Make a swift exit

The advice from the scientists of CIRCE (Conservation, Information and Study of Cetacean,, the Spanish-based team studying the Iberian orca, as well as the Spanish government, however, is for an active rather than passive defence.

If you must pass through a danger area, then transit in daylight and under motor. If attacked, yachts should apply full power to leave the area of attack, preferably heading for shallow waters, as fast as possible.

CIRCE scientists have been seeking out orca encounters to test which deterrents and evasion tactics work best. Photo: James Kenning

CIRCE provides this advice from empirical data collected during structured experiments with the orcas aboard their research vessel Nashira. The theory is not just conjecture; it has been tested over numerous encounters in which Nashira has purposefully been ‘placed at risk’. The orcas will continue to attack the boat but, once separated from the main feeding group by 0.5 to 1 mile, will give up the chase and return to the family unit.

The advice is repeated daily on the Telegram forum – if attacked, leave the area as fast as possible. Do not waste time with countermeasures such as dropping sails and going into reverse, or deploying sand over the stern; minimise the time within the interaction zone by powering away from the main orca group.

Skippers are obliged to report orca incidents to the coastguard

Other orca deterrent tactics

Note should be made of the numerous countermeasures being discussed by cruising sailors. These vary in their impact on the marine environment and, more to the point, their legality. It is noted that the Iberian orca is a protected species in both Spain and Portugal and that both countries have laws in place regarding how boats can interact with these endangered animals.

The use of anti-predation ‘pingers’ is illegal in both countries and is now thought to be ineffective. Firecrackers, although legal to purchase in Spain, are prohibited for use if deployment will harm an orca’s acoustic ability. Pouring diesel over the side of the boat is an environmental hazard, though deploying a bucket of sand off the stern may be seen as a non-destructive deterrent. Often discussed online, shooting orca clearly falls well outside the law for a number of reasons.

For all these methods, however, the advice is clear – avoid the known areas of orca activity. If caught unawares, leave the area as fast as possible even if still under attack.

Reporting orca incidents

It’s worth noting that Spanish regulations require you to report anything that could pose a risk to navigation, and that includes orca interactions, which should be reported to the Spanish coastguard/MRCC.

Finally, a note regarding the work of the Cruising Association to collate and analyse structured data of both eventful and uneventful passages through the orca danger areas of Biscay, Atlantic Portugal, the Algarve and the Gibraltar Straits. Success of this project is dependent upon the quality and quantity of reports submitted by skippers who have made passages such that a level of statistical confidence can be attributed to the various theories and hypotheses regarding this growing problem. The reports can be accessed by CA and non-CA members alike, and all skippers are requested to submit passage reports at

Orca deterrent measures

If orcas interact with your vessel, take the following measures if possible without creating greater danger:

  • Keep people away from the sides of the boat, ensuring they have the best possible protection against sudden movements of the vessel, falling into the water, or displaced loose items.
  • It is always preferable to navigate under engine rather than sail. Avoid stopping the boat. Navigate in a straight line at the highest possible speed (within constraints of vessel and conditions) towards shallower water until the orcas lose interest.
  • For sailing boats, stability may be affected if the keel is damaged, and it is therefore better to motor rather than sail.
  • Navigate as close to the coast as it is safe to do so for your vessel, particularly within Barbate Bay.
  • Any vessel in the presence of orcas or cetaceans must comply with Royal Decree 1727/2007 of December 21, which establishes measures for the protection of cetaceans, especially for avoiding the behaviours that could cause death, injury, disturbance, or distress to the cetaceans.
  • Observe, and if safe to do so for the vessel, crew and orca, take photographic records of the individual orca involved.
  • Follow any further advice issued by the government to sailors.
  • Every skipper has the obligation to report any incidents that may pose a danger to navigation. Interactions should be reported through the corresponding Maritime Rescue Coordination Centre.

Until it is understood why orcas are targeting boats, finding which deterrents are effective is hit and miss. Photo: Yuri Smityuk/Getty

GTOA Safety protocol

  • Disconnect autopilot to avoid damage and let the wheel/tiller run free.
  • Keep hands away from wheel or tiller to avoid injury.
  • Stop the boat, de-power and drop or furl your sails.
  • Contact the authorities on VHF 16 or by phone on 112. If you receive no response on Channel 16 then use the telephone or in the approaches to Gibraltar try the shipping control channels ‘Tarifa Traffic’ on Ch10 (or Ch67 if busy) or ‘Tangier Traffic’ on Ch69 (or Ch68 if busy).
  • 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 photograph or video evidence whilst 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 before any interest is sparked by moving off.

Risk factors

  • Depth of water: Stay in shallow water. There are very few reports of interactions in water less than 20m. There may also be a reduced risk within 2 miles of the shore and in less than 40m of water. Sailing close inshore may increase other navigational risks, especially in the event of boat damage.
  • Antifoul: Possibly slightly higher risk with black antifoul, and lower with copper antifoul, but there is no statistically significant difference.
  • Autopilot: The noise may increase the risk of an attack, but this is not yet proven. A strike on the rudder can also damage the autopilot.
  • Day/night: Interactions happening both day and night, with only a marginally reduced risk seeming to be shown at night, but resultant rescue at night is harder.

Disengage the autopilot to avoid mechanical damage, though rudder stops may then also be vulnerable. Photo: Graham Snook/YM

Deterrent measures

  • Many deterrent measures are discussed on social media and mentioned in skippers’ comments in reports submitted to the CA. No reliable, legal measures have yet been proven.
  • Reversing: Going backwards in the presence of orcas is considered illegal by certain authorities, except in the case of emergency, and is always illegal when there is intent to harm an orca. In 29 reports of boats reversing, 16 found it a successful tactic, 11 did not. If using this tactic, do so as soon as orcas are sighted rather than after contact is made.
  • Sand: Orcas use echolocation to ‘see’ their surroundings, navigate and hunt. Some fishermen have been known to throw sand in the water to create a haze to disrupt the orcas’ echolocation ‘vision’. As long as the sand is not thrown at the orcas directly, it is harmless and a tactic GTOA considers worthy of testing.
  • Noise: The use of deterrent pingers is illegal without licence as it can cause hearing damage to the orcas, and can increase vessel-orca collisions. The few who have used it and reported back to the CA have confirmed failure. Other noise on board has had mixed results. Out of nine reports received on attempting to deter orcas by making noise, five succeeded and four failed. It is also possible that making noise may extend the interest of orcas.
  • Playing dead: The GTOA advises that ‘playing dead’ would calm the orcas’ heart rate. CA data shows that the interactions where crews followed the ‘playing dead’ protocol lasted longer than those who did not. However, research undertaken by GTOA indicates that the level of damage to the yacht is marginally less when ignoring the orcas.

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