luc wrote:
Hi folks,

I just relaunched my boat after painting the bottom, installing new
zincs and instruments. That was in March of this year. Around the 1st
of July, I scrubbed the bottom in preparation for a race, and noticed
the zinc on the strut was nearly gone, despite only having been in the
water 3 months. Someone tells me this is because I need an isolator.
What is an isolator, and how does it work? Big picture and simple
answers preferred.

thanks,

Luc

The galvanic isolator goes in your AC ground line (the green wire) and
prevents your zinc, which is presumably connected to your boat's AC
ground wire via the boat grounding systems, from trying to protect your
neighbors' boats, the dock and any other immersed water in the vicinity.

The shore power green wire goes to the isolator as it's first connection
in the boat.

Alternatively, disconnect your shore power.

bob