assessment of the behavioral responses of C.carcharias when encountering a non-lethal electric field many times stronger than what they would naturally experience. Upon their first observed encounter, all C. carcharias were repelled at a mean (± std. error) proximity of 131 (± 10.3) cm, which corresponded to a mean voltage gradient of 9.7 (± 0.9) V/m. With each subsequent encounter, their proximity decreased by an average of 11.6 cm, which corresponded to an increase in tolerance to the electric field by an average of 2.6 (± 0.5) V/m per encounter. Despite the increase in tolerance, sharks continued to be deterred from interacting for the duration of each trial in the presence of an active Shark Shield. Furthermore, the findings provide no support to the theory that electric deterrents attract sharks. The results of this study provide quantitative evidence of the effectiveness of a non-lethal electric shark deterrent, its influence on the behaviour of C.carcharias, and an accurate method for testing other shark deterrent technologies. In reviewing the 2016 University of Western Australia research, the Australian Geographic magazine published an article titled “Great White Shark Deterrent almost 100 Per Cent Effective”. In 2016, a study conducted by the Australian consumer advocacy group Choice found that Ocean Guardian (Shark Shield) was the only independently tested shark repellent to be effective. In 2018 the New South Wales state government funded research conducted by Flinders University to test the Effectiveness of five personal shark deterrents for surfers. Flinders tested five personal shark deterrents developed for surfers Ocean Guardian FREEDOM+ Surf, Rpela, SharkBanz bracelet, SharkBanz surf leash, and Chillax Wax) by comparing the percentage of baits taken, distance to the bait, number of passes, and whether a shark reaction could be observed. A total of 297 successful trials at the Neptune Islands Group Marine Park in South Australia, during which 44 different white sharks (Carcharodon carcharias) interacted with the bait, making a total of 1413 passes. The effectiveness of the deterrents was variable, with the FREEDOM+ Surf affecting shark behaviour the most and reducing the percentage of bait taken from 96% (relative to the control board) to 40%. The mean distance of sharks to the board increased from 1.6 ± 0.1 m (control board) to 2.6 ± 0.1 m when the FREEDOM Surf+ was active. The other deterrents had limited or no measureable effect on white shark behaviour. Based on the power analyses, the smallest