1. In a small saucepan, combine the water and maple syrup; bring to a boil over high heat. Once mixture boils, turn off heat and add mint. Place in the refrigerator for 25 to 30 minutes, or until cool.
2. Slice watermelon and discard green rind. Cut red flesh of watermelon into chunks and place in a blender; blend on high for approximately 60 seconds, yielding approximately 5 cups juice. Using a large mesh strainer, strain mixture over a large bowl, discarding any solid pieces.
3. Remove mint from cooled maple syrup mixture and discard. Combine maple syrup mixture and watermelon juice; stir until thoroughly mixed.
4. Fill 6 to 8 large glasses with ice. Split club soda and watermelon mixture evenly among each. Mix and serve.