Thanks Chuck.

Wasn't there someone in one of the rec.boat groups that was
complaining about zincs and other metalic deterioration happening
after a new client at their marina moved in?

Found out he wasn't using shore power as of to say, but rather a
permanently plugged-in , ungrounded battery charger, and several
boats around him were starting to develop an unseemingly fast
corrosion.

it makes sense to me.....