Combine the blueberries and raspberries in a bowl. Half fill 12 x 80ml (1/3 cup) popsicle molds carefully with berries. Combine the juice and coconut water in a jug. Pour into each mold, so it almost covers the berries. Freeze for 30 minutes or until partially frozen.
Insert a paddle-pop stick into the centre of each mold. Add the remaining berries then fill with remaining juice. Freeze for 6 hours or overnight if time permits.