Stray Current Corrosion
Stray current corrosion occurs when electric current escapes from its intended path, which is normally through the wiring, and uses your boat, or its underwater fittings, as the new path. Even a moist surface can carry stray current. It can occur due to poor connections, failing insulation, improper support of wires and improper original installation. This is a more severe kind of corrosion than galvanism and causes very rapid metal loss. Stray current corrosion can and does sink boats by corroding through-hull fittings. And it can do so in less than a week.