Name:   Shortbus - Subject:   tragedy in Sandy Date:   7/12/2021 10:04:14 PM

As far as technical stuff, GFCI breakers and outlets compare current going out to current going back into it.  If enough current to hurt someone as a difference is pulled,   ----click-----   it goes off.

The four wire power versus three wire power might also help.

Neutral is ground potential but carries current. This means there is always some voltage between a current carrying neutral and ground.

For four wire systems, you get two ground potential wires, one carrying power and one not.  Should give a "colder" ground.

If you feel "pins and needles" like your leg is asleep,  SWIM AWAY from the electrical source.

To test your grounds, take a 100w light bulb and connect from each hot to grounded metal cases.  It should light up bright.

You can also take a quality voltmeter and test your ground to the water directly with each probe.

An isolation transformer is safest and practical for smaller loads.

Using 12 volts for as much as possible also works.

220 volts is usually not more of a shock hazard than 110v.

My condolences to the family.  Hopefully some of this might save someone.