Preheat Grill To Medium Heat. Grill Brats Just To Brown, Then Cut Into 2 Pieces. In 10-Quart Pot, Bring Beer, Water, Seasoning, And Onion To A Boil. Add Potato And Bratwurst. Cover And Cook 15 Minutes. Add Corn, Cover And Cook 3 Minutes. Add Shrimp, Cover And Cook 5 Minutes Or Until Shrimp Is Done, And Sausage Internal Temperature Is 160 Degrees F. Serve All With Melted Butter And Lemon Wedges.