Preheat oven to 375 degrees. In a large bowl, cream sugars and butter or margarine. Add eggs and water. Beat well. Mix flour, baking soda and salt well. Add gradually to egg mixture. Chill dough overnight (it is important that the dough be well chilled). Wrap each mint completely in cookie dough. Place 2" apart on lightly greased cookie sheets and put a nut half on top of each cookie. Bake 7-9 minutes until golden brown. Allow to cool thoroughly on wire racks.