1 (12 fluid ounce) can club soda, or as needed
1 1/2 fluid ounces white rum
1/2 fluid ounce orange vodka
ice, as needed
1 splash vermouth, or to taste
1 strip of orange peel
Fill a cocktail glass halfway with club soda.
Combine rum and vodka in a cocktail shaker. Add ice, cover, and shake until chilled. Strain into cocktail glass with club soda. Garnish with a spritz of vermouth and orange peel.