[Highlander]

Hi guys

I have an "impressed current system" that monitors the voltage of the water vs the boat and somehow adds or subtracts from that to protect the expensive aluminum bits in the water. It has a titainium reference pad and another pad that looks like zinc.
Last season the indicator lights showed "under protected" and the normal zincs wore very rapidly. Usually they dont wear much at all.

Over the winter all the connections were checked and cleaned and now- as the boat sits in Rhode Island the light shows green.

Two weeks ago the boat was tied up at our normal home dock and the lights started flickering green-red.

The question is where do you start? I assume that the dock power system or a nearby boat can cause the problem. How far away can a boat be and cause corrosion problems to my boat?
Can you measure a voltage from the dock ground to the water?

The problem can also come from my boat? Would a similar aproach to the ground fault question be valid?

Thanks

Carl