Scrub and coarsely grate the beetroot. Zest the oranges. Slice the white pith from the oranges and discard it. Halve the oranges and flick out any pips. Slice 1cm off the ginger and finely chop it.
Add the beetroot, oranges and ginger to your blender with a few ice cubes. Pour in the coconut water. Blitz till smooth, adding a splash of ice cold water for a thinner consistency, if you think it needs it.