This is a riff on our-low proof grapefruit wine spritz — just made to be nonalcoholic! Grapefruit is always refreshing in a spritz, an extra-dry ginger ale keeps the drink bright, and the bitters ensure balance.
Swap option: You can replace the soda water and Angostura bitters with Sanbitter, a bright-red nonalcoholic Campari-like soda from San Pellegrino.
Fill a highball glass with crushed ice; add soda water and bitters (or Sanbitter). Top with ginger ale and grapefruit juice.
Stir to combine, then garnish with half of a grapefruit wheel.