Creamy Watermelon Pie

I love to make this when we have watermelon. It's cool and refreshing!

1 pkg (3 oz.) watermelon gelatin
1/4 cup boiling water
12 oz. Cool Whip, thawed
2 cups cubed seeded watermelon
1 9" graham cracker crust

In a large bowl, dissolve gelatin in boiling water. Cool to room temperature. Whisk in whipped topping; fold in watermelon. Spoon into crust. Refrigerate for 2 hours or until set.