Shore power ground question?

[Jaymatthews]

I just bought a 89' Marlin 28 with brand new Zuk 250's with helm master, new garmin electronics, trailer etc. This old girl is in great shape for her age! I am chasing down some old wiring for lights, pumps,etc. I am adding new bilge, wash down and bait pumps. I plan to get my Bennet trim tabs working. and remove all the old, unneeded wiring. I want to make sure I am good to go for going offshore which can be 80 miles here in the Carolinas. That said, I found a green wire that appears to be 12 gauge. It was ran through the pipes on my hard top and into the electronics box but was not hooked to anything. Under the dash, it was split and another lead went toward the switch panel. Again, not hooked to anything. I pulled all of this out and traced it back to the stern. It was hooked to a bolt in the bottom that comes through the hull. There are 2 bolts there and I assume this is a grounding plate as there is a plate on the bottom of the boat in this location. It could be a Zink but not sure. The shore power is hooked up and ran through a Galvanic isolator. That all seems to be wired correctly. I am just wondering what the purpose for this other ground wire would be and did I mess up pulling it out, even though it was not hooked to anything? I have read that it could have been hooked to the old Lowrance system (i found evidence it has one at one time) or it could have been hooked to an SSB radio. Any ideas? Should anything else be hooked to that plate?

 

[SkunkBoat]

Yes probably ground for SSB