1 oz. light rum 1 oz. gold rum 1 oz. dark rum 1 oz. lime juice ½ oz. pineapple juice ½ oz. grapefruit juice ½ oz. grenadine syrup 1 sprig fresh mint Mix all the ingredients except the mint into a pitcher and stir well to combine.Into a glass add crushed ice and pour over the cocktail. Serve garnished with fresh mint.