Should You Wear Protection?

Demand for anti-shark devices has surged, but do they actually work?

| posted on February 25, 2014
The reality of whether these shark-deterring technologies remains to be determined. But that doesn't mean people are averse to trying them out.

The reality of how effective these shark-deterring technologies are remains to be determined. C’mon, still pretty cool though.

In the months following a flurry of shark attacks on Maui, anti-shark devices on the Valley Isle have been flying off the shelves. “We’re having trouble keeping them in stock,” said Dennis O’Donnell, owner of Hawaiian Island Surf and Sport, who has kept a waiting list on the product since December. “Because we had so many shark-related incidents here last year, the demand for these products has really sky-rocketed. We have a list of more than two dozen people waiting for them.”

When it comes to shark attacks in Hawaii, Maui has borne the brunt of the blow (eight of the 14 statewide attacks occurred there) creating the surge in demand for a product that could protect surfers and beachgoers. The most popular anti-shark devices, which come in a variety of sizes and range in price points, typically retail between $400 and $700. O’Donnell’s shop carries two different products, the ESDS, which is based in Hawaii and Shark Shield, a company based out of Australia. Both products operate under the theory that electromagnetic fields can deter sharks.

The premise behind the devices is relatively simple: All sharks have small, gel-filled sacs called the Ampullae of Lorenzini, which are located in their snout and can sense electrical current emitted from prey. Both the ESDS and the Shark Shield produce an electrical field that, from Shark Shield’s website, “cause the shark to experience muscle spasms and a high level of discomfort, which causes it to turn away from the electronic field, effectively repelling the shark and protecting the user.” Shark Shield, the older of the two products, originally created the product for divers and included a braid-like chord that produced the electromagnetic field. In recent years, they (along with ESDS) have created a product that wraps around your ankle, similar to a leash, designed specifically for surfers.

But do these devices actually work?

The maker’s of Shark Shield point to multiple research studies and testimonials that back the science behind their product. However, some shark experts remain unconvinced that the devices comprehensively deter shark attacks. Dr. Carl Meyer, of the University of Hawaii’s Shark Research Center, is one of them.

“There are a variety of anti-shark products out there. Some have a theoretical base and some are just nonsense. The devices based on electromagnetism [like the Shark Shield] have some potential. But I’m hesitant to say that they’re completely effective. I still believe that there needs to be more exhaustive, independent research done before we can come to any concrete conclusion.”

In a 2012 study conducted by Flanders University and the South Australian Research and Development Institute (SARDI), researchers tested Shark Shield’s Freedom 7 device, which is typically wrapped around the ankle of the user and trails an antenna that distributes an electronic pulse. The study found mixed results that leaned on the positive side, with researchers concluding that the shark shield did indeed have an effect on shark behavior (it took the sharks longer to take the bait and deterred many of sharks from taking the bait at all) but “it did not deter or repel them in all situations nor did it repel all individual sharks.”

When questioned by the Cape Argus, a South African news site, Dr. Alison Kock, who was involved with the study, said that “The combined results of the study indicate that while the risk of an attack may be reduced wearing a shark shield, the shields failed to repel great whites in all cases.”

While not concrete, the studies conducted seem to show that anti-shark devices like the Shark Shield do indeed work to some effect. “We believe the SARDI research as very positive, most people don’t read the whole report and often only report on half the results,” said Shark Shield’s Lindsay Lyon. Shark Shield has posted a series of YouTube videos explaining the positive notes from the research. While very confident in the effectiveness of their product, they were also quick to point out that the device isn’t a full-proof solution, but a deterrent: “Electronic shark deterrents are a safety device and there isn’t a single safety device that can guarantee your safety. People die wearing seat belts and safety helmets…”

Dennis O’Donnell of Hawaiian Island Surf and Sport, the store with the waiting list to purchase the devise, echoes this sentiment. “Whenever we sell an anti-shark device in our shop, we’ll give the customer as much information as possible and let them make the decision. We let them know that they’ve been proven to be effective, but they’re not going to provide you with a guarantee against being bit. But at the end of the day, the ocean’s not Disneyland. There’s always going to be risk. And the best thing you can do is to be smart about when and where you’re surfing. That’s the biggest deterrent.”

  • Jimmy the Saint

    When the sea looks sharky is the only time you are happy to see a crowd!

  • Kit

    My God what a sad invention!!! Oceans are NOT our natural territory, if you want to submerge in this non-human element then you’ll have to take the risk, if you don’t want to take that risk then STAY HOME on your couch and play video games..quite safe and you have tons of lives! It’s not enough that we trash the oceans with tons of chemicals and trash, that we fish them empty and derange/hurt the creatures living there by producing extreme noises that travel miles under water…no now we have to wear”security shields” when going surfing which probably hurt the sharks and maybe other creatures and can change their behaviour, which could have a huge impact on their feeding (talking about fish here,not surfers..or how many surfers have been entirely eaten by sharks…hm?! Don’t think they even like us really..) and hence impact the whole environment…but sure go ahead! Just hope they don’t decide one day to enter our “natural” living sphere and do the same to us!

    • Jimmy the Saint

      I surf in an area which doesn’t have any sharks (I am just after putting a hex on myself) and I disagree with you, this is potentially a great invention for shark preservation. If there was a reliable shark repellent then West Australia wouldn’t be culling sharks. This technology would probaly save a lot more sharks than humans if it was perfected!

      • Kit

        Yeah I see your point but it’s still a big intrusion into their habits and the problem is there’s still so many more sharks being killed for other reasons (like shark fins) where this would not change anything..

        • T

          I think this is the least of our problems when it comes to the environment…. Sow up that bleeding heart dude.. That shit will make you dinner in the wild.

    • surf&diddle – all i do

      maybe the ocean is a non-human element to you, you landlubber

  • Gandhi Warhol

    Article in Spring 2014 “Big Island Traveler” magazine by on how to avoid a shark attack

    and how a NON ELECTRONIC shark repellent works and may be more accurate. Had to share this because unlike Dennis O’Donnell, they literally refer to O’ahu as “Disneyland for surfers” in the opening paragraph.

  • joblo

    Kit: Your talking crap, don’t talk about fish and shark behaviour when you don’t know what your talking about and have no scientific evidence to back up your statements. I am a marine research scientist for over 20 years and have had to dive in some of the most dangerous locations on this planet…..”you’ll have to take the risk, if you don’t want to take that risk then
    STAY HOME on your couch and play video games..quite safe and you have
    tons of lives!”….for that comment you should be fed to sharks, with frikin laser beams. This technology deters sharks from a specific location….a couple of meters around you, the only feeding behaviour it will modify is the misidentification of humans as a food resource and therefore will save lives…..of sharks and humans. They could be used instead of nets and drum lines that capture and kill many sharks as well as many other animals including turtles and dolphins. For someone like myself, I can do research where it would normally be too dangerous (like inshore seagrass meadows in the tropics, Shipping Port’s channels and inshore coral reef systems with virtually no visibility….or should I just stay home and play video games…

    • libra8r

      How do you spell “you’re”?

      Hard to imagine any place could be “normally too dangerous” for you. You must work alone. A lot.

      • EmilyGoodall

        Um . . . does anyone out there know of a repellent for trolling grammarians?

      • Richo Eden

        shove your stupid spell check where the sun do not shine…kook

  • Aaron Lujan

    Amazing Device !

  • Lagun

    Let the statistics do their job. The probability is so small.

    • tim

      I believe we need to cull the great whites to the brinks of extinction take them off the endangered list lets hang em on walls theyre becoming far to commonly sighted at beaches there are to many of them and we have enough other predatory sharks to fill that void n clean our water ways BUT….on the note of the shark shield watch videos guys they clearly do work the sharks dont like them and thats clear to see you dont have to be a f×÷king marine biologist with a big head to see that the proof is there for you to see with your own eyes sharks dont waste energy setting up an attack mode charge at something just to bail off at the last second unless theres a shark shield on … i live in western Australia’ we’ve had 6 meter whites swimming in our estuarys weve also had alot of attacks im a diver and wont go in past knee without my shark shield i have a wife and kids and at just an added 1 % chance my shield might save me and let me see my kids at the end of the day 700 bux is nothing to pay .id pay $7000 if thats what it cost i might only be alittle protection from sum sharks but its a lot better than none

      if you dive or swim deep in west or south australia your in the natural migratory path for every great white in the oceans of this world your playing a game of russian roulet every time you hit the water il take my little electronic gaurdian angel over loosing life or worse limbs any day

  • zeepee

    I think the biggest “threat” sharks have on a majority of surfers is the fear factor they implement (due to the very small number of surfers that ever get attacked)… therefore by eliminating the fear one can feel, they eliminate this potential “threat”. So if you want to have the peace of mind, or illusion of peace of mind (science has yet to prove anything substantial) and spend $400-700 dollars to do so, then that’s each persons decision. But isn’t that what people are being convinced they need to buy? Say in the case of a home security system… its more about the illusional sense of security than that actually protecting someone’s home. And for some people the peace of mind is worth the price… not sure if this made any sense haha

  • Grinder

    What about using the underwater speakers (around major swimming beaches or carry a portable one) that transmit killer whale attack calls and scare them off?? It was featured on 60 minutes here in Jan 2014. Very effective.

  • elvislivesmaui

    maui needs few sharktaco stands.

  • Shane

    This one uses sound:

  • atee

    I don’t know why you would pay between $400-$700 for an anti-shark device when there much more cheaper alternatives out there. For instance, sells shark repellents for just over $25 and they seem to work better than the $500 devices on the videos on their site

    • Logan

      I’ve bought several shark shields and I got to say while the videos look convincing the actual product quality is not good , they stop working within the first 2 to 3 times you use them Not happy at all at this time with the product. Hope a serious company picks up the idea and does something solid with it

  • Head Candyass They also do shark repellent board shorts, shark repellent bathing suits, and shark repellent wetsuits. Also shark repellent surfboards.

    Anyone else is doing so unlawfully because only owns the trademark. Promoting other companies is like unethically bootlegging subpar music or film.

    Only has done the extensive research backed with countless TV appearances and shark experts on this subject.

    Thank you Andrew VanWyngarden of MGMT and superstar surfer John John Florence for endorsing shark repellent rashguards by .

  • Shark guy

    A marine research scientist should know the difference between ‘your’ and ‘you’re’.

    • Richo Eden

      not if he does not care…hell most of us don’t

  • Emile Gerber

    Easy, cover yourself in chum and fish guts, attach the device to your leg(make sure it’s charged) and jump into great white infested waters. Concrete conclusion?