2In a large bowl, dissolve the watermelon gelatin in the boiling water by stirring for one to two minutes until fully dissolved. Let the gelatin cool to room temperature.
3Finish the pie
4Once cooled, whisk in the thawed whipped topping until smooth. Gently fold in the cubed watermelon until evenly mixed. Spoon the mixture into the graham cracker crust, spreading it evenly with a spatula. Refrigerate for at least two hours, or until the pie is fully set, before serving.