[Jhellwig]

Easiest thing to check for would be current on the grounding conductors in the dock electrical in both Ac and Dc. Another issue could be a chemical in the water in that area.

You could check the usage rate on the anodes if you measures the current from the anode to your boat. You could also check the voltage impressed on the boat by the galvanic system. I don’t know what the ideal voltage is for whatever metal your boat is but steel should be lower than -.8 volts to a half cell.




Oh and the depletion of the zinc anode is what provides your cathodic protection. Galvanic isolation is a coating that prevents erosion from galvanic currents not anodes.

 

[gpop]

Any overhead high voltage lines?

 

[oldsparky52]

Man, it's been a while since I've looked at this. From what I remember, most often this is a "hot" boat (miswired).

When you say galvanic isolator, are talking about one of those devices you install on your shore power input to block DC?

If the whole marina is suffering, then I might look for some stray current in the water. Have you checked for current on the grounds feeding the power centers?

How about a step voltage check in the water?

Did you check for voltage from the ground conductor to the water without the boat plugged in? I've always had a concern with the PoCo service using the waterway (ICW around here) as a parallel path for current back to the substation. If they have a deteriorating neutral connection in their system, I can envision current flowing through the ground system into the boat and then into the water on it's way back to the substation.

If you dive into this, may I recommend you have a written log of your findings because you will get into so much information it will be difficult to recall it all accurately.

I hope you will share your findings with us as you move through this.

 

[macmikeman]

She'll be fine just as soon as you get her down to Grenada..............