Bring 1 cup carbonated beverage to a boil.
Add to gelatin and stir until dissolved.
Add water to remaining carbonated beverage to make 3/4 cup liquid; stir into gelatin mixture.
Chill until thickened; then fold in diced melon.
Pour into 4 cup mold and chill until firm about 4 hours.
Garnish with prepared dream whip whipped topping and mint leaves, if desired.