Put pineapple in a blender and blend until it is of a pulpy consistency.
In a saucepan combine pineapple, sugar, water and salt.
Bring to a boil and simmer Soak gelatin in 2 tbsp water.
Add to pineapple mixture and chill.
Stir in rum and fold in whipped cream.
Pour into a pineapple shaped mold and freeze.
Unmold and surround with rum soaked pineapple rings.