I have an older 17 foot aluminum boat with a small console and a 35HP Mercury. There is a compartment under where I sit that has the battery and gas tank. There is a ground wire that is attached to the frame of the boat that goes to the battery. The boat spends most of its time in fresh water at the dock behind my house. From what I have read, I believe it is probably a bad idea to have the negative terminal of the battery hooked up to the hull. Should I disconnect and remove it or continue to use it. Why would it be setup that way in the first place?