Watermelon and Cucumber Tonic

A new interpretation of the familiar gin and tonic, this cocktail features fresh watermelon and cucumber juices for a refreshing taste.
Combine the watermelon halves, mint, juice, and cucumber in a blender or food processor; beat until smooth. Place 4 layers of cheesecloth on a fine sieve so that the cheesecloth extends around the edges; strain the watermelon mixture through the prepared sieve into a bowl, reserving the juice mixture. Gather the edges of the gauze together. While holding the cheesecloth over the sieve, squeeze out the remaining juice. Avoid dry substances. Repeat the procedure with the remaining watermelon, mint, juice and cucumber.Combine 2 1/2 cups of the juice mixture, tonic water, and gin, mixing well. (Save the remaining juice mixture for another use.) Serve with ice.