Halve the papaya and scoop out the seeds. Discard them. Scoop the flesh into your blender. Coarsely grate the carrots and add them to the blender as well with the mint leaves.
Zest the blood orange. Slice the pith from the orange and discard it. Chop the flesh and add to the blender with the zest. Pour in the maple water and add a cupful of ice. Whizz till smooth.