fstbttms wrote:
My personal opinion is that a galvanic isolator is never a bad idea. However, I also think the "hot harbor" is a wive's tale. You can go to virtually any marina anywhere and find somebody who will say it's "hot" there. I have heard this in virtually every marina I have ever worked in in the Bay Area, and I have yet to find it to be true. Marina-wide problems are rare, IMHO. That being said, if you are plugged into the shorepower system, your boat is in electrical contact with every other boat on that particular circuit and you can be sharing somebody else's electrical problems. But in reality, if you are experiencing rapid zinc depletion or corrosion issues, the most likely cause is aboard your own boat and that's the place to look first.
A friend of mine was told by a mutual friend and boat owner that he was moving to another marina downriver.* His diver told him that his anodes were being disolved because of electricity in the water from a train bridge about a mile up river (this is not an electric train).
I call BS, but I didn't talk to the diver personally.
If you have a problem with your anodes or underwater metal and the other boats in your marina do not, you should probably look for a problem on your own boat or possibly the individual pedestall you are plugged into.