For our purpose, stray current corrosion is the eating away of underwater metal fittings that occurs when there is a leak from a hot wire allowing current to find an alternate path to ground. This alternate path could be through standing water or damp areas in the bilge of your boat, or through the seawater surrounding your boat. It can originate from any direct current DC or alternating current AC source within your own boat, from dock power centers or fittings, ship-to-shore cables, or from any of the boats moored at the dock.
In all cases stray current corrosion can have a very negative impact on the well being of your boat.
Why is it so negative?
Galvanic corrosion can set up currents between fittings. These currents are usually
measured in milliamp and millivolts (thousandth of an amp or volt). Over time these low
current flows can eat away at your underwater fitting - eventually causing a fitting
failure - a natural phenomenon.
On the other hand, a leak to ground from your boat's DC or AC electrical system can set up current flows hundreds of time greater than that produced by galvanic corrosion. These high current flows can destroy fittings in days - a near natural phenomenon.