A reader describes this as "watermelon-scented water." The flavor doesn't overpower, but refreshes, especially on hot days.
6 cups seeded, cubed watermelon
8 cups water
1/2 cup sugar
1/2 cup fresh lime juice
Garnish: watermelon wedges
Process watermelon in a blender until smooth. Pour mixture into a large bowl; stir in 8 cups water, sugar, and lime juice. Cover and chill at least 8 hours. Stir; serve in tall glasses. Garnish, if desired.