Trim the ends of the blood orange and slice into ¼” slices. In a wide frying pan, whisk the water and sugar together and bring to a boil. Reduce heat to medium low and stir until the sugar dissolves. Add the blood orange slices in a single layer and keep at a low simmer. Allow to simmer in the syrup until the white pith of the orange becomes translucent, about 40-60 minutes depending on the thickness of the slices. Turn them carefully about halfway through. 

In the meantime, place a wire rack over a parchment paper lined baking sheet. When the slices are ready, remove from the syrup, allowing any excess syrup to drip back in the pan. Place on the wire rack and allow to cool, uncovered, until they are dry. This may take up to 24 hours. 

Once dry, cut the candied slices in half. Place the chocolate in a heatproof and microwave safe bowl.  Microwave in 20-30 second intervals until melted. (Alternatively, set the bowl over a pan of simmering water until melted.)  Line a small baking sheet with parchment. Carefully dip each candied blood orange half into the melted chocolate, shaking off any excess.  Place on the parchment paper and sprinkle with flaky sea salt. Allow the chocolate to set. Serve!