DSK wrote:
To avoid corrosion an isolation transformer is the best option. Be
sure not to
tie the grounds on both sides together. Incoming circuit ground goes
to
the transformer case, the other goes to your vessel ground, such that
no
DC current can pass from shore power to the vessel. With such a system
you can crank up all AC appliances and forget about corrosion.

An excellent idea for more reasons than just this one.
Isolating the grounds can be a life saver. Unfortunately
these are rather expensive little bits of gear... our boat
does not currently have one, but it's on the list.

Fresh Breezes- Doug King

Prices have dropped. I got one slightly banged up for $250
and a dual voltage one for around $500 that I intend to set up
for both US and European power.