Remove the frozen watermelon cubes 5 minutes prior to making this recipe.
Place all the ingredients into a powerful blender (such as a Vitamix).
If you have a 'Frozen Dessert' setting on your blender, simply use that to blend, otherwise start blending on medium speed and work your way up to high. While blending, constantly push the contents of the blender down into the blades with a temper. Add more coconut water as needed to blend, but add as little liquid as possible to keep your freeze thick!
Pour or scoop out into your favorite glass and and top with or swirl in Chia Seeds if using! Serve and enjoy immediately with a spoon and straw!