Slice limes into quarters and squeeze the juice of one fruit into each serving glass, throwing the limes into the glass along with it. (Only use half of a lime instead of 2 medium limes if you prefer a drink that's not as tart.)
Add 1 tbsp sugar and one shot (2 Tbsp // 30 ml) of white rum to each serving glass and muddle until well mixed.
*Only add half of a lime if you prefer a less tart drink.
*If your watermelon isn't frozen, just add in a few actual ice cubes to chill the drink.
*You'll have enough watermelon ice cubes for at least four drinks.
*Omit the sugar if you prefer a more tart cocktail.
*I highly recommend eating the boozy watermelon cubes as they melt - so tasty!
*Questions about substitutions, equipment, or troubleshooting? Check out our Recipe FAQ page.
*Nutrition information is a rough estimate.