Start by preparing the watermelon. Cut a small watermelon in half, scoop out the flesh, and dice it into cubes until you have 4 cups.
In a blender, combine the diced watermelon, coconut water, ice, lime juice, and honey/agave syrup (if using).
Blend on high speed until the mixture is smooth and frothy. Stop and scrape down the sides of the blender to ensure all ingredients are well combined.
Taste the frappe and adjust the sweetness by adding more honey or agave if desired.
Pour the Coconut Watermelon Frappe into tall glasses and garnish with fresh mint leaves if desired.
Serve immediately and enjoy the refreshing taste!
For a creamier texture, consider adding a banana to the blender before blending.
If making in advance, store the frappe in the refrigerator for up to 24 hours, though it's best enjoyed fresh.
Feel free to experiment by adding other fruits such as strawberries or pineapple for a different flavor profile.