Grapefruit & Watermelon Mocktail Cooler
Purée watermelon and lime juice in a blender until smooth. Strain mixture into a pitcher to make 4 1/2 cups (1.125L) watermelon juice.
Pour evenly into 8 (8 oz/250 mL) glasses with ice and 4 mint leaves. Top with soda and garnish with a watermelon wedge.