The electrolysis corrosion pictured below was caused by electrolysis. All electrolysis is eliminated with the SeaBis System.
The cause of each electrolysis corrosion appears below each photograph.
However the same effect has many causes.
Where electrolysis exhibits a gray coating, then electrolysis is flowing in two directions, at different times.
The SeaBis System makes all wet fittings, the hull / engine etc. electrically open circuit.
In Home terms we pull the (electrical) plug
out of the socket.
Fit the SeaBis System - its most the economic way for you to protect your vessel.
Bilge pump. This is very common. The wires to the bilge pump lay in the bilge moisture and insulation becomes conductive. Another very common cause is a crimp lug connecting the bilge pump lying in the bilge. Always lift wiring clear of the bilge moisture.
Note: The semi-regular shape is very common. When sheet metal is rolled areas become more electrically conductive - have a lower resistance to electric current - so electrolysis passes through those areas easier than the remainder of the sheet.