The last thing I would want is to be a connecting link for a ground loop over 700' apart at the ends, especially with one end being a body of water. It would really be a total waste to bypass the transformer's excellent isolating properties and the fact that it is now a separately derived source. I would want to maintain the feeder side ground clear into the transformer enclosure. You would definitely want a L-L or L-G fault to clear and need to get back to the source for that. The only thing I would tie that ground to might be some primary surge protection for the transformer. My goal for the secondary grounding would obviously be to be at a zero potential difference with the water. One would also think that this would be closer to the ideal ground than 2 rods in clay up on some cliff. Now, can you buy a grounding electrode boat anchor???
Joe
