I have a water heater on my boat. I have the old heater element that apparently broke and was removed and where it was is caped with a plastic plug. I would like to make it work again. I would like a 120 volt element that plugs into an outlet on the boat while i am at the dock. My tank is a stainless cylinder about 6 gal. It has no name or brand or part # on it. I am wondering if it is home made. Where can I find an element for this. Does it have to be marine grade? It has a 1 1/2 in thread opening that it screws into the tank. I have been to defender with the old element and they have not been able to help. I am willing to text someone a pic if they think they can help.