HONOLULU (HawaiiNewsNow) - Pro surfer Joel Centeio believes in the small device he straps to his ankle when he takes to the water.
"It just gives me that sense of safety. And I feel comfortable when I'm wearing it," he said.
The tiny box on the Velcro strap is called the Electronic Shark Defense System or ESDS.
Wilson Vinano created the lightweight machine. He said it emits an electric pulse that repels sharks by affecting the gel in a shark's nose.
Video on the his web site shows sharks dodging a bag of fish when the device is nearby, then shredding it to smithereens when the unit is taken away.
"We tested it on divers, our divers that swam around with it with sharks around. The sharks would just fade away. They wouldn't even attempt to come close," Vinano said.
He worked on the ESDS for five years and field tested different versions for hundreds of hours.
Collin Kobayashi of 3D Innovations and other engineers perfected the unit, making it watertight, compact and streamlined.
"We took all of the different parts that go in here. And then we tested it to make sure it fits. Once it fit we were able to send that file to get tooled up," he said.
The device is about the size of a deck of cards and weighs about seven ounces. It runs on a battery that lasts nine hours before it needs a recharge.
Other shark repellent devices are bigger. Vinano said the ESDS is universal.
Centeio uses his religiously.
"Not only surfers, but divers, just normal beach goers could use it," he said.
"Get your devices," Vinano said. "It will help you feel more confident in the water than worrying about sharks."
The Electronic Shark Defense System costs $335 with a surf leash and $299 without one. It goes on sale Monday on Vinano's web site, www.esdshawaii.com.