Electric shock drowning is a term used in the US to describe a cause of death that occurs when swimmers are exposed to electric currents in the water. In some cases the shock itself is fatal, since the person will suffocate when their diaphragm is paralyzed, while in others it incapacitates the swimmer causing them to drown. The main cause of electric shock drownings is faulty electrical wiring on boats or piers that causes electric current to leak into the water. Electric shock drownings occur most often in fresh water, which is conductive due to dissolved minerals and impurities. The increased conductivity of saltwater reduces the fraction of the electric current that flows through a submerged person, whose body has a much smaller conductivity than the saltwater. In this case, the current to cause electric shock drowning would be so great that current-limiting circuit breakers would trip and shut off the current, thereby protecting against electric shock drowning in saltwater.[1][2]
Sometimes Electric Shock Drowning is referred to as ESD, but this should not be used as it can be confused with the IEC-defined abbreviation for electrostatic discharge.[3] For some reason, the accident type is prevalent only in the USA.[4]