Swimmers and Shark Deterrents: Do They Really Work?

Sharks are a real concern for swimmers along California's coast. After a shark attack near Lovers Point in 2022, the Kelp Krawlers swim club started using shark deterrents. These devices are supposed to keep sharks away. But do they really work? Erica Fox, a member of the Kelp Krawlers, was found dead near Davenport in December 2025. She was wearing a shark deterrent. This has made people wonder if these devices really make swimming safer. Shark deterrents come in different types. Some use magnets, others use electricity or scents. Sharkbanz is one of the most popular brands. It claims to reduce the risk of shark encounters. But the company also says it can't stop ambush attacks. Research on these devices is mixed. A 2018 study found that most deterrents don't work well. Only one device, Freedom+Surf by Ocean Guardian, showed a big reduction in shark interactions. Sharkbanz and Rpela disputed these findings, citing their own studies.Carl Meyer, a marine biologist, says shark deterrents have a big flaw. The electromagnetic field they create is only effective at very close range. By the time a shark detects it, it might be too late. Many swimmers know the limits of these devices. But they still use them. Lisa Jensen, a Kelp Krawlers member, admits they give a false sense of security. Sharen Carey, another member, says they use the devices even though they know they might not work. Sharkbanz compares their devices to seat belts or bike helmets. They say these devices reduce risk but can't protect someone all the time. After Fox's death, the company said there's no way to prevent ambush attacks. The truth is, shark attacks are rare. But when they happen, they can be deadly. Shark deterrents might not be the solution people hope for. Swimmers should be aware of the risks and take precautions.