Originally Posted by offline2004
What can I do/should I do to protect my prop and boat. From what I understand this could be coming from my boat or one near by me in the marina?
Are there things that I need to check and are there steps I can take to protect this?
As previously mentioned, keep an eye on your zincs. Everything working as it should, in a saltwater environment you should get 6-9 months out of them. Significantly more or less is indicative of a problem. There are many factors that can affect zinc life. The most common ones are electrical problems aboard your own boat. If you notice rapid zinc depletion, have a marine electrician go through your boat's system to see if he can pin down a cause. Installing an isolation system can help protect you from external causes of electrolytic corrosion. Again, a marine electrician can advise you on this.
If your boat lives in a freshwater environment, it is important to note that anodic protection should be provided by magnesium anodes, not zinc. The zinc anodes do not have enough electrical potential to overcome the greater resistance inherent in freshwater.