In a large bowl, using a hand mixer, whip heavy cream until soft peaks form.
Whisk in condensed milk. Evenly divide the cream base into 3 separate bowls.
In a saucepan set over medium heat, add raspberries and water. Cook until berries have burst, about 3-5 minutes. Remove the pan from the heat and cool for 5 minutes.
Place a mesh sieve over one the bowls of cream. Add the raspberries and using a spatula to press on the mixture so that the seeds are caught in the strainer.
Using a blender, puree mango until smooth. Add mango puree to the second bowl of cream.
Add pineapple to the third bowl of cream.
Mix each flavor until uniform in color.
Alternating each flavor, layer the 3 flavors into a freezer-safe loaf pan. Once all flavors are added, use a butter knife to gently swirl the sherbet. Be careful not to over stir, making more than 5 passes with your knife.