colas said..ptsf1111 said..
Yup, depending on which query you put in Google, you'll either find resources that tell you it deters sharks, or others stating it will actually attract them (and put others at a heightened risk).
Importantly, there are studies, but their results depend greatly on the shark species. Some sharks do not even use electric currents to hunt...
"The threshold for an electrical field to repel a shark can vary by species but ranges from about 3 V/m (to deter bull sharks) to 18.5 V/m (to deter scalloped hammerheads), with some species requiring even higher field strengths.
The key challenge, however, is to create an electric field that extends far enough into the surrounding water. Generating long-range electric fields in seawater is inherently difficult because seawater is highly conductive. The electric current disperses rapidly through the surrounding medium, causing a voltage gradient that drops sharply with distance."
spectrum.ieee.org/electric-shark-repellentOr: " 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 behavour. "
pmc.ncbi.nlm.nih.gov/articles/PMC6120439/Also, beware of the studies that select specific species because they respond well to the electric devices... They are not wrong, but their results may apply differently to other species.
"The bonnethead shark, Sphyrna tiburo L. 1758, was selected as the study species due to ease of acquisition and husbandry coupled with their documented use of the electrosensory system when hunting "
onlinelibrary.wiley.com/doi/10.1111/jfb.70220 
