Stir crumbs, sugar and melted butter in bowl. Press over bottom of 9-inch springform pan and up sides.
Combine lime juice and water in saucepan; sprinkle gelatin over top. Let stand 5 minutes to soften. Stir sugar, eggs and rind into pan. Cook, stirring, over medium heat until almost boiling, about 7 minutes or until instant-read thermometer reaches 160 degrees F; do not let boil. Remove from heat.
Beat butter and cream cheese in large bowl until well mixed, 1 minute. Gradually beat in lime mixture until well blended. Refrigerate, stirring, until mixture thickens enough to mound slightly when dropped from spoon, about 45 minutes.
Beat chilled cream in small chilled bowl until stiff peaks form. Fold into lime mixture. Pour into prepared crust. Cover; refrigerate until firm, 3 to 4 hours.
Run thin knife around inside of pan to loosen sides; remove side of pan. Garnish with whipped cream and lime slices if desired. Store in refrigerator. Makes 16 servings.