Place watermelon, lemon juice and lime juice in blender container; cover. Blend on high speed until smooth. Strain mixture through fine mesh sieve.
Place basil in large pitcher, muddling gently with a wooden spoon. Pour fruit juice mixture into pitcher. Add cold water and simple syrup, stirring to mix well.
To serve, moisten rims of 12-ounce beverage glasses. Dip in Watermelon Lime Finishing Salt to coat. Fill with ice. Pour mocktail into prepared glasses. Garnish with lime wheels, if desired.
