Electrolysis on Yachts: What Causes It and How to Catch It Early
Electrolysis is one of the more deceptive threats a yacht can face. It works quietly below the waterline, corroding metal components long before any damage becomes visible. By the time most owners notice a prop, shaft, or fitting has deteriorated, the problem has usually been progressing for a while. What Causes Electrolysis on Yachts Electrolysis occurs when stray electrical current escapes a boat's wiring and travels through seawater seeking a path back to ground. Along the way, it attacks underwater metal components, including propellers, shafts, thru-hulls, trim tabs, and rudders. Common causes include: Faulty marine electrical systems or damaged insulation Improper shore-power connections or reversed polarity Corroded terminals or unbonded circuits Poor grounding systems that allow current to leak into the water Electrolysis vs. Galvanic Corrosion These two issues are often confused, but they're mechanically different. Galvanic corrosion occurs naturally when di...