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.
“Playing dead” can make the interactions last longer. However, the Grupo Trabajo Orca Atlantica, an organization that’s been studying this pod of orcas, found that it can result in less damage. 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 GTOA wants more information because it conflicts with their findings, according to the CA.
Orcas are also pretty speedy, swimming 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. One person told the CA that they returned immediately after the sand had dispersed into the water.
Throwing sand might be worth testing, according to GTOA. Sand can cloud the water, and interfere with orcas’ ability to echolocate. It should be otherwise harmless to them, per the CA.
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.
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 is met with mixed success. 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 as well.
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,” Alfredo Lopez of GTOA 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. It seems that adding liquids to the water to try to dissuade them is ineffective, and could be harmful to these mammals.
Pouring gasoline or diesel fluid and urine into the water had no effect, according to the few sailors who tried it. Four bottles of urine were thrown overboard by one person. In their report, they stated that “urine had ZERO impact.”
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 don’t think there is a way to completely deter orcas. She said that orcas are well adapted to the environment. “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.”