What happens in a large body of water (ocean etc) when an electric shock accidentally slips out or a live electric cable is cut? Is it similar to an underwater grenade going off, affecting a large area, or is it not a worry?
If that power cable would be completely cut, the electricity would spark from one of the pole of the cable to the other, until some breaker shuts the thing off.
Even at great energy, the impact would be minimal.