Very refreshing, delicate and nicely balanced. We thought that 6 drops of Rose Water wasn't too much and that, to complement the basil, a dash of Angostura enhanced the garnish (both in appearance and taste). As a 'stiffer backbone' version, an added 15ml Havana Club Original Rum worked for us and we suspect that Vodka might do so as well...at that volume we don't think that the spirit overpowered the elegant play between watermelon, lemon, basil and rose. Anyway, bravo. It's interesting how, when juiced, watermelon expresses a hint of bitterness. We served it in a Collins glass, where it sat very comfortably.