1Cut each watermelon slice into 10 wedges. Cut rind from wedges and remove seeds. Refrigerate about 1 hour or until chilled.
2Cut each pear into 4 pieces; remove cores and stems. Place pears and rum in blender or food processor. Cover and blend on medium speed about 1 minute or until smooth.
3Arrange watermelon wedges on 8 dessert plates. Top with blackberries. Top each serving with pear puree.