Anode Replacement
Inspect and replace anodes in the water (Anodes help deter corrosion caused by electrolysis)
Also having your running gear/any metal parts (intake covers, metal rudders, props, shafts, trim tabs, etc…) regularly inspected is the best way to catch electrolysis before it becomes a major issue causing serious damage to any metal on the vessel below the waterline or to any neighboring vessels. It doesn’t matter if the dock itself has power or not— 12V/DC improperly grounded or a hot wire that can trace back to a component that leads underwater can make electrolysis happen.