In a small bowl, combine the coconut water and chia seeds. Stir well and let sit for 30 to 35 minutes.
Meanwhile, in a small pot over low-medium heat, combine the blueberries, sugar, and lemon juice. Smash the blueberries with a fork and stir frequently. Let cook until the mixture gently bubbles, about 10 minutes.
Add the acai powder and stir until dissolved. Remove from heat and let cool. Add the chia mixture, mix well, and store in the refrigerator for at least 6 hours or overnight.