When I had my boat surveyed (back a number of years ago), the surveyor remarked that I should have a ground fault outlet. I did not think that a bad idea and put in on the to do list. I just installed one and it does not work. My question is the is thus: the green wire is the ground (hopefully). To what is it grounded (if it is)to. What should I be looking for or should I think I intalled a defective outlet?