Take all the ingredients in a cocktail shaker filled with ice and shake it for 30 seconds or so.
25 ml Bacardi Carta Blanca Rum, 10 ml Bacardi Carta Negra Rum, 5 ml Grenadine, 25 ml Orange Juice, 25 ml Pineapple Juice, 10 ml Cranberry Juice, Lots of Ice Cubes