This is no simple ELI5 answer because there are many, many factors to consider.
However, you can roughly [calculate](https://www.reddit.com/r/askscience/comments/2wb16v/how_far_can_electricity_travel_through_water/copcl05?utm_source=share&utm_medium=web2x&context=3) the “safe distance” from something like a toaster in the ocean. And that’s roughly 77 meters, or ~250 feet, for a 120v toaster.
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