Place watermelon and honey in a high-speed blender. Blend on high, until smooth and juicy. Pour into ice cube molds and freeze until solid, at least six hours or overnight.
Rinse the blender and dry completely. Add all ingredients (except ice cubes) for the coconut slushie base into the blender. Mix on high until fully incorporated. Pour into ice cube molds and freeze until solid, at least six hours or overnight.
Once all the cubes have frozen, remove them from the molds and put them into ziplock bags separated by flavor.
Blend the coconut cubes in a high-speed blender with about six cracked ice cubes. If you have one, use a blender tamper to compress the cubes as they blend. The end result will be a thick slushie with the texture creamy snow or an icy soft serve. Transfer to a bowl and place briefly in the freezer while you blend the watermelon cubes.
Rinse the blender and dry completely. Blend the watermelon cubes, using a blender tamper to compress the cubes as they blend. The end result will be a slushie with the texture of snow.
Remove the coconut slushie base from the freezer and layer both watermelon and coconut slushie bases in glasses, serving as you like.