2 12 lbs seedless watermelon, rind removed and diced (about 7 cups)
1 cup fruit-sweetened cranberry juice (sometimes called cranberry nectar)
14 cup fresh lime juice
1 lime, cut into 6 slices
Place the melon in a blender or food processor. Process until smooth. Pass the puree through a fine-mesh sieve placed over a bowl to eliminate the pulp and clarify the juice. Pour the juice into a large pitcher. Add the cranberry and lime juices and stir to combine. Refrigerate until very cold. Pour into tall chilled glasses and garnish each with a fresh lime slice.