aprils

We are having a Softub 300 delivered this week. I have a question about the electrical part of this. I know we can plug this into a regular outlet, we have one that is on the wall outside the house. The receptacle on the house has a metal cover, but is not weatherproof while in use. So I know we'll need to replace that, but I was looking at the softub cords have the thick GCFI circuit box on the end, how on earth do you protect that box from the weather?? Or do I not need to??