Use a sharp knife to peel the pineapple. Cut around the core to make pineapple wedges and discard the core. Cut the wedges into large chunks.
Add the pineapple chunks, water, and orange zest into a blender. Blend until smooth.
Place a fine mesh sieve over a bowl and strain the juice to remove any fleshy pieces. Dilute with additional water if needed. Pour the juice into serving glasses filled with ice cubes and garnish with fresh pineapple slices or wedges.