In a blender, combine watermelon, chopped mint and club soda. Pulse for about 60 seconds, until no chunks remain. (If using a watermelon that has seeds, strain before serving to remove.)
Scoop ice cream into two glasses, pour watermelon mix over, and enjoy.
Recipe by pretty plain janes at https://prettyplainjanes.com/2013/07/31/watermelon-mint-soda-floats/