+x Philip Heaton - 2/28/2020DickThank you for this. When we had the boat in build we had long discussions about this issue and an isolation transformer is of course superior to a galvanic islolator. Our thinking was that we would spend most of our time at anchor and visit marinas rarely, which has proved to be the case until the last couple of years, and so weight and cost could be a consideration. The GI could provide the main hull protection. It seems from what you are saying that I had better keep on checking with our trusty reverse polarity test plug and have the reverse reverse polarity lead at the ready.Best wishes Phil