Remove the seeds from both of the melons. Scoop the pulp from the melon with a melon baller. Set the melon balls aside.
Remove the remaining pulp from the melons. Add to a blender and puree with the raspberry syrup and ginger ale in a blender.
Pour in the soda, and mix again. Fill the glasses with ice cubes, and top with the melon cocktail. Garnish with the reserved melon balls, and serve.