Start by peeling the pineapple, removing the core and slicing the pineapple into large chunks. Transfer the large pineapple chunks to a blender, then add in the diced mango.
Juice the lime into the blender, then add in 1 cup of water. Blend for 1 minute on high speed until smooth.
Strain this mixture into a large pitcher, then add in the remaining 5 cups of water.
Stir in ¼ cup of sugar, then taste and adjust. Let chill in the refrigerator for 1 hour, before serving over ice. Garnish with a pineapple wedge or mango slices.