Shaft anodes (all with reinforcement) Wide Type: Shaft Ø 19mm Ext. Ø 55 mm Length: 65 mm Weight: 0.79. Most corrosion problems on your ship below the waterline are galvanic corrosion. Galvanic corrosion occurs when 2 metals with different potentials are electrically connected to each other and immersed in an electrolyte (salt water), the metal with the lowest (least noble) potential will automatically form this anode and the one with the highest will form the cathode. The anode will then normally sacrifice itself for the cathode. It is not only where there are 2 different metals put together that anodes and cathodes are formed. When, for example, steel sheets are manufactured, they are not completely homogeneous and will then locally form anodic and cathodic areas.
