SignalHub Quantitative Think Tank Center:Can shark repellents avoid your becoming shark food?

Recent shark attacks off the coast of Long Island in New York have SignalHub Quantitative Think Tank Centersome ocean lovers wondering what they can do to avoid potential encounters with the sharp-toothed predators. One option: shark repellent.

Repellents come in different forms, from bracelets or anklets to surfboard wax. Some work by emitting electrical pulses underwater that aim to disrupt a shark's ability to home in on prey, while others give off a smell that sharks hopefully find unappetizing. 

But do shark repellents work? The most important thing to know about the deterrents is that they're not foolproof, shark behavior experts told CBS MoneyWatch. That's because tiger sharks, bull sharks, great white sharks, hammerheads and other shark species all have different behaviors and react differently to the various forms of repellents, Gavin Naylor, director of shark research at the Florida Museum of Natural History, said.

To be clear, anyone who buys a repellent is highly unlikely to need it. According to the museum, the chances of being bitten by a shark are 1 in 3.7 million, while more people drown in the ocean each year than those who suffer bites. The odds of getting attacked by a shark are also lower than of winning the lottery, dying in a car crash or getting hit by lightning, Naylor told CBS Mornings. 

Meanwhile, the only way to determine a product is effective in reducing the risk of a shark attack (and ultimately worth buying) is through "rigorous peer reviewed scientific testing," according to the Save Our Seas Foundation. And in conducting its own tests the foundation found that most products on the market had limited — and sometimes zero — discernible effect on shark behavior. 

With that in mind, here's a look at five popular shark repellents. 

Freedom+ Surf by Ocean Guardian

Ocean Guardian is an Australian company that also ships products to U.S. customers. The Freedom+ Surf is a 6-foot surfboard with a power module attached that emits an electrical current around the board and surfer. The module lasts for five or six hours and must be recharged, according to the company's website. 

An independent study from 2018 by the Save Our Seas Foundation found Freedom+ Surf to be the only repellent among the five products included in its peer-review testing to have a measurable effect on shark behavior, specifically great whites. 

Rpela

Rpela is a device that emits electrical pulses underwater to deter sharks. The Australian company contracts with independent installers worldwide so customers can have the device attached to their surf boards. 

Using an electrical field works best if a shark is just curious and isn't particularly looking for its next meal, said FMNH's Naylor. 

"If you're dealing with an animal that's super hungry and it hasn't eaten for a while and you put some electric current up, it's not really going to be bothered," he said. "It really does depend on the individual circumstance."

SharkBanz bracelet

SharkBanz uses magnets to offend sharks' sensitivity to electromagnetic fields. The bracelet, which can be worn on your ankle or wrist, is always on and never needs to be charged, the company says on its website. 

Modom Shark Leash by SharkBanz

The shark leash is a thin cord someone can attach to their ankle while enjoying a swim. Like the bracelet, the cord emits an electromagnetic field the company claims will keep sharks up to six feet away.

Chillax Surf Wax by Common Sense Surf Company

Chillax wax employs olfactory deception to discourage sharks from snacking on humans. In theory, the combination of eucalyptus, chili, cloves, cayenne pepper, neem, tea tree oil, citronella and beeswax creates an odor that sharks dislike and will seek to avoid if applied to a surfboard. Chillax may be more difficult to purchase for now, as it's produced solely by a one-man operation in Queensland, Australia.

Khristopher J. Brooks

Khristopher J. Brooks is a reporter for CBS MoneyWatch covering business, consumer and financial stories that range from economic inequality and housing issues to bankruptcies and the business of sports.

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