Electrochemical corrosion of metals is one of the most destructive processes that affects a boat during its lifetime.
Cathodic protection is designed to prevent corrosion by altering a metal's electrochemical characteristics through
the application of electrical current by the use of ZINC ANODES or impressed current.
Your boat's underwater metal fittings such as propellers, shafts, struts, and thru-hulls are susceptible to electro-
chemical corrosion.
There are several types of corrosive influences:
Galvanic Corrosion
Galvanic Corrosion occurs when two or more metals with different galvanic voltages are electrically connected through a bonding system and by current carrying fluid.
It is the result of the more active metal's natural tendency to give up
electrical current to the less active metal.
Galvanic corrosion may occur in fresh or salt water but will not occur in pure water.
Stray Current Corrosion
Stray Current Corrosion occurs when underwater metals are energized by an electrical current that has strayed from an electrical conductor or device powered by a battery, generator or dock power. It is the result of an electrical fault.