Orcas in some regions, particularly the Iberian orcas near the Strait of Gibraltar, have been increasingly interacting with boats—sometimes aggressively. While researchers at the Orca behavioural Institute, Centre of Whale Research and other scientists are still studying this behaviour, several theories attempt to explain why orcas might target vessels more frequently.

Possible Reasons for Increased Aggression

1. Learned or Playful Behaviour (Most Likely Theory)

• Orcas are highly intelligent and social animals, capable of learning and passing behaviours to others.
• Some experts believe a few orcas started playing with rudders, and others copied them.
• This could be a form of play, training, or social bonding, especially among younger orcas.

2. Retaliation for Negative Experiences (Revenge Theory)

• Some researchers speculate that one or more orcas may have been injured by boats, leading to a learned response of targeting vessels.
• A female orca nicknamed “White Gladis” has been identified as a possible behaviour leader, possibly after a traumatic event.
• This could explain why they target rudders, a key part of the boat’s movement, as if trying to stop or disable them.

3. Stress from Environmental Changes

• Overfishing in the region has reduced the orcas’ primary prey—bluefin tuna—which could increase stress levels.
• Noise pollution from boats and shipping traffic may affect their communication and behaviour.
• Some orcas might react aggressively due to a lack of food or environmental stressors.

4. Curious & Experimental Behaviour

• Orcas are known for testing objects in their environment.
• In the past, orcas were observed playing with crab pots, kelp, and even ice chunks. Now, it seems some have discovered rudders.
• This may have started with curiosity but evolved into more widespread behaviour.

5. A Cultural Shift Among Orcas

• Different orca groups have unique behaviours, almost like “cultures.”
• The Iberian orcas might have developed this as a new trend, much like how some orca groups teach each other specific hunting techniques.
• This would explain why the behaviour is increasing among younger orcas.

Should Sailors Be Worried?

• Most orcas are NOT aggressive toward humans—they focus on boats, not people.
• However, the risk of rudder damage, stranding, or costly repairs is real.
• Researchers are studying how to discourage this behaviour without harming the orcas.
• In the meantime, sailors are advised to avoid orca hotspots and use passive deterrents, such as stopping their boats when approached.

Practical Ways to Avoid Orca Encounters in the Mediterranean & Atlantic

If you’re sailing in areas where orcas have been interacting with boats (such as the Strait of Gibraltar, Gulf of Cádiz, and Portuguese coast), taking precautions can reduce the risk of an encounter or damage.

1. Plan Your Route to Avoid Hotspots

• Check recent orca activity reports before setting sail. Useful resources include:
  
  • GT Orca Atlantica (Telegram & Facebook groups with real-time reports)
  • Orca Attack Reports on Facebook
  • Local coast guard & marine advisories
• If orcas have been recently spotted in an area, consider delaying your trip or adjusting your route.

2. Avoid Sailing at High-Risk Times & Conditions

• Most incidents happen between May and October when orcas are more active in the region.
• Sail in shallow waters (if possible)—orcas tend to stay in deeper channels.
• Many encounters happen during daylight; consider sailing at night in high-risk zones.
• Pay additional attention to your passage planning.

3. Reduce Attraction to Your Boat

• Lower Your Speed:
  
  • Fast-moving boats seem to attract more attention. Reduce speed in high-risk areas.
• Avoid Using the Autopilot:
  
  • Some sailors believe orcas recognize predictable movements and target autopiloted vessels more often. Steering manually may help.
• Reduce Noise & Vibrations:
  
  • Engine noise might interest orcas. If safe, switch to neutral and drift if orcas approach.
• Sail in Groups:
  
  • There is some evidence that orcas target solo boats more frequently than those in groups.

4. If You Encounter Orcas

• Immediately Stop the Boat:
  
  • Drop sails, stop the engine, and let the boat drift. Many sailors report orcas lose interest when the boat stops moving.
• Turn the Rudder to One Side:
  
  • This makes it harder for orcas to access and damage it. Heave to if you need to.
• Stay Inside the Boat:
  
  • Avoid standing near the stern, where orcas often target rudders.
  • Don’t swim with orcas; full stop.
• Do NOT Make Loud Noises or Try to Scare Them Away:
  
  • Banging on the hull or using sound devices can increase curiosity or escalate aggression.
• Wait it Out:
  
  • Most encounters last 15–30 minutes before the orcas leave.

5. Prepare for an Emergency

• Have Backup Steering Options
  
  • If the main rudder is damaged, carry an emergency rudder, drogue, or steering oar.
• Know How to Call for Help
  
  • VHF Channel 16 for Coast Guard assistance.
  • If you lose steerage, you may need a tow.
• Consider Deterrent Methods (Experimental)
  
  • Some sailors are testing metal chains wrapped around rudders to discourage attacks.
  • No proven deterrents exist yet, but researchers are studying ways to prevent these encounters safely.

Final Thoughts

The best strategy is to avoid encounters. Stay informed, adjust routes accordingly, and remain calm if an interaction occurs.