Larry wrote:

Once the isolation transformer is between the boat and the power company,
the boat only needs TWO WIRES!..the ones to the secondary 120VAC winding!

The boat still needs 3 wires just like before. One side of the
secondary of the isolation transformer will now go to the BOATS ground
system, including the green ground wire on the boat. The secondary of
the isolation transformer is treated the same way as your generator
system when feeding the boat.

Regards
Gary