Add watermelon cubes to the blender and blend until smooth, about 30 seconds.
Pour the watermelon puree through a fine-mesh strainer into a pitcher to remove pulp.
Mix in lime juice and honey, stirring until honey dissolves.
Add sparkling water just before serving. Stir gently to combine.
Fill glasses with ice cubes and pour the mixture over them.
Garnish each glass with fresh mint leaves and watermelon wedges.
Notes
Store leftover watermelon puree mix in the fridge for up to 2 days without sparkling water.Add sparkling water right before serving to keep the drink fizzy.For extra sweetness, adjust honey to taste.Choose ripe, sweet watermelon for best results.Make ice cubes from watermelon juice to prevent drink dilution.