Orcas have been ramming, damaging, and sometimes sinking boats in the Strait of Gibraltar.
From fog horns to bottles of urine, sailors are trying some wild ways to save their yachts.
Some techniques are more successful than others.
Late last month, orcas sank another yacht. The "Grazie Mamma II" was sailing off the coast of Spain and Morocco when a pod of orcas zoomed up and started attacking its steering fin for 45 minutes, Insider reported.
The crew was safe, but the boat sank once it reached port. This latest sinking adds to the hundreds of incidents of orcas interacting with, damaging, and sometimes sinking boats over the last three years.
The Cruising Association, which collects these reports, and scientists studying this pod have found that some strategies are more successful than others. It's also worth noting the CA cautions on its site that some methods may be distressing or harmful to the marine mammals and should be avoided.
1. Playing dead
Many experts recommend stopping your boat, turning off the engine, and dropping sails.
Some anecdotes report that "playing dead" can make the interactions last longer. Alfredo López, a team member of the Grupo Trabajo Orca Atlantica, an organization that's been studying this pod of orcas, told Insider in an email that the best thing you can do is stay quiet. That's the GTOA's official recommendation.
This, like many other techniques, has mixed results, though.
Of the 231 boats that reported physical contact with an orca, scientists found that 63% of boats that were lightly damaged didn't follow the silent protocol, according to a report from the Orca Behavior Institute in June. But for severely damaged boats, the results were nearly split down the middle.
2. Driving away fast
In June, the Spanish government published advice that included driving away from the animals as fast and safely as possible "until the orcas lose interest."
The recommendation is based on one scientist's interactions with the mammals, but López said that this method is dangerous and illegal, because it contradicts laws meant to protect the animals.
López also said this method could be futile, because orcas are pretty speedy. They can swim as fast as 30 miles per hour, so boats would have to move swiftly to outrun them.
3. Creating a sandstorm
Based on a few reports to the CA, sailors have found success with throwing sand behind the boat as orcas approach. The CA noted that it can't yet corroborate these accounts.
"I deployed sand when heard them around the stern but this had a temporary effect only. They returned almost immediately after the sand dispersed in water," one person reported to the CA.
López said if this works, it does so by clouding the water, interfering with the orcas' echolocation. Though the GTOA doesn't officially recommend this technique, López said it should be harmless to the whales.
4. Reversing the boat
Unless it's an emergency, it may be illegal to make sudden changes in speed or direction when orcas are near, according to GTOA. This could harm the animals.
But if you move the boat slowly, and without sharp turns, so as to avoid hurting the whales, the GTOA may recommend this method, López said.
Orcas can't swim backward, "so if you start going backward, it's harder for them to approach the boat from behind and get to the rudder," John Burbeck, a member of the CA, told The Washington Post.
Yet this maneuver has been met with mixed results. In February, the CA said that 29 skippers tried the technique, and just over half, 16, found it a successful way to avoid an orca interaction.
5. Making noise
Some boaters have used loud noise to try and scare the orcas away. The same person who reported throwing sand said, "the sound of the fog horn was the most effective to make them go away."
Cruisers have also reported using firecrackers or banged on their boats. While firecrackers seemed to work, it's illegal and may harm the orcas and their hearing, The Washington Post reported.
The same is true for underwater "pingers" that send out acoustic signals. GTOA discourages their use, and López said that sometimes, making more noise made the orcas ram the boat more.
Some researchers are working on noise deterrents specifically for killer whales that will safely stop them from interacting with boats.
"Adding more noise into the ocean can be harmful to living things," López told Insider earlier this year.
6. Dumping liquids, like urine, into the water
Sailors have seemed to resort to increasingly desperate measures when orcas repeatedly ram their vessels. Trying to deter them by adding different types of liquid to the water seems particularly ineffective and potentially harmful to the mammals.
This method directly contradicts laws enacted to protect the species and is bad for the environment, López said.
Pouring gasoline or diesel fluid and urine into the water had no effect, according to the few sailors who tried it. One person reported that they poured four bottles of urine overboard. "Urine had ZERO effect," they wrote in the report.
Dumping a black water tank filled with a "bleach solution" seemed to provoke the orcas into ramming the boat more, according to one account.
Regardless of your preferred technique
If orcas damage your boat, the GTOA recommends calling the authorities. Try to stay out of the water because although orcas don't generally want to eat humans, you could risk getting in the middle of their ramming.
"I think they just think humans are some odd thing, certainly not food, and not really anything that they are bothered by," whale researcher Hanne Strager previously told Insider.
And ultimately, no matter what you do, if the orcas are interested in your boat, you may be hardpressed to avoid them, Lori Marino, marine mammal neuroscientist and founder and president of The Whale Sanctuary Project, told Insider in an email.
"I'm not sure there is any full-proof way to deter the orcas. They are perfectly adapted to their environment," she said. "I would caution, however, that boaters not consider any deterrence methods that could be harmful to the orcas or any other animals in the ocean."
This story was originally published on November 9, 2023. It has been updated.
Read the original article on Business Insider