Watermelon Pie

1 (3 ounce) box watermelon jello
1/4 cup COLD water
12 ounces Cool Whip, thawed
2 1/2 cups diced watermelon

Mix well the watermelon jello and cold water. Add Cool Whip, and mix well. Fold watermelon into mixture. Pour into 9-inch prepared graham cracker pie shell. Refrigerate at least 3 hours before serving.