Handheld eSpear is designed to deter sharks with an electrical field
Since at least 2004, surfers, swimmers and scuba divers have been able to buy an electronic shark-deterrent device known as the Shark Shield. Its patented technology is now being offered in a handheld speargun-like gadget, called the eSpear.
Developed in Australia, the original Shark Shield is worn on the thigh or ankle, or it can be mounted on a surfboard. Once in the water, it forms a three-dimensional electrical field around itself. The claim is that when sharks enter this field, their electro-receptive system is disrupted, causing them to experience muscle spasms and severe discomfort. Although they're not actually harmed, they are motivated to immediately leave the area.
Sydney-based Ocean Guardian's eSpear utilizes that same system, but it takes the form a "gun" that can be carried in an optional thigh holster, then pulled out when needed. If users think that a shark is getting a little too close, they squeeze the trigger. Doing so causes a forward section of the device to slide/pivot out from the main body, exposing two electrodes to the water. This, in turn, instantly creates an electrical field surrounding the device, measuring 1 meter across by 2.5 m in length (3.3 by 8.2 ft).
As compared to the existing Shark Shield, advantages of the new device include the facts that it only runs (and uses up its battery) when manually activated, and it can be pointed right at approaching sharks. It presumably isn't as effective at guarding against sneak attacks from unseen sharks, however.
And then there's the whole question of how well the deterrent system actually works. Well, a 2016 study conducted by the University of Western Australia determined that the Shark Shield deterred attacks on a bait-loaded canister 90 percent of the time. And in a 2018 study conducted by Australia's Flinders University and Fox Shark Research Foundation, it performed the best out of five commercially-available devices.
Obviously, though, users would still be wise to take all the usual precautions when entering the water.
The eSpear weighs 250 g (8.8 oz), is operational to a depth of 100 m (328 ft), and runs for a claimed one to two hours per wireless charge of its lithium battery – run times will be affected by water temperature. A built-in LED display lets users know when the battery is getting low.
Should you be interested, it's currently the subject of an Indiegogo campaign. A pledge of US$165 will get you a device, when and if it reaches production. The planned retail price is $299.