Ingredients

　　Pulp from 2 1/2 pounds watermelon, seeded, cut into pieces, and chilled

　　1/2 to 1/3 cup lime juice, or to taste

　　3 tablespoons superfine granulated sugar

　　3 teaspoons orange-flavored liqueur

　　1 cup plus 2 tablespoons dark rum

　　In a blender, or in a food processor fitted with the steel blade, purée watermelon, lime juice, sugar, orange-flavored liqueur and rum until smooth, and divide among chilled stemmed glasses.