Chris wrote:
If youb boat is not connected to shore power or ground,
I don't see how the marina's or other boater's faulty electrical
installation could eat your zincs.

Chris


Well, if your boat is in a strong DC field between
two other boats, that could speed up zinc depletion.

Imagine the boat on your right dropping his
battery cable into the water and current flowing
through the water to the boat on your left, and
returning to the battery via the shore power
grounding conductor. Your boat is in the middle
and current enters a through-hull at the bow,
travels through the DC wiring to the prop and out
again. The current seeks out a low resistance path
and your boat is it. Now you have a strong DC
voltage at the prop that cancels the effect of
your zinc and eats the prop.


Impressed current systems on docks or larger
vessels can create such fields also.

Chuck