I would like to convert my shore power pedestal to be more like marinas I might visit..  ie add a GFCI like new marinas so I can make sure my boat will not trip GFCI ( and to make sure my dock/boat is safe for swimmers near my dock). I have a Newport Harbor Mate Power Pedestal that is about 15 years old. It has a single 50 amp 125/250 VAC, a single 30 amp 125 VAC and a dual 20 amp 115 VAC outlets. It has phone and ethernet connections. I use the 50 amp 125/250 VAC outlet for my boat; I do not use the 30 amp 125 VAC outlet.. Internal to my boat, I have two 50 amp circuits; one circuit is for three air conditioners and the other 50 amp circuit is for all other 115 VAC loads. Not sure what to buy or how to install a GFCI considering the 50 amp 125/250 VAC is two hots, one neutral and the green ground.  Anyone have any ideas?  I emailed the manufacturer but did not hear back... Jim Gano