Cut the watermelon into 1-inch chunks. Remove any black seeds.
Add watermelon, peach slices, lime juice, and honey to the blender.
Blend until smooth, about 30 seconds.
Pour the mixture through a fine-mesh strainer into a pitcher.
Add coconut water and stir well.
Fill tall glasses with ice cubes.
Pour the mixture into glasses.
Add 2-3 mint leaves to each glass.
Garnish with watermelon wedges and peach slices if desired.