This is an extensive and complex technical subject. As long as everything is going smoothly, you usually don't hear anything about it. Anodes are replaced once a year. If they are of the correct size and there are no unusual currents around where a craft is moored, then there are no problems. The situation gets more complicated in the event of premature, perhaps unusual wear or if we find ourselves with a propeller that looks like the ones in these photos... Apart from the expense that will have to be borne, in order to replace the part it will be necessary to understand what might have gone wrong. CSN will provide you with the support you need to make sure it doesn't happen again!