is caused by forcing DC current
to flow between two metal objects immersed in an electrolyte such as sea water
. The source of current
can be the DC battery
system or it can occur naturally due to the chemical composition of the two metal parts
in question. The former is usually called electrolytic corrosion and the latter galvanic corrosion. The device is aimed at the former not the latter. But the mechanism of corrosion is the same in either case.
However, the device they are promoting might actually work as a way to identify sources of stray forced current. It does nothing to eliminate that stray current as far as I can tell. You have to eliminate the source of leakage current yourself. I have my doubts that a lay boater could use this device effectively. They claim a guarantee of success in many places of their literature. That usually makes me suspicious but that's just me.