Prepare the watermelon by cutting it into small cubes and removing any seeds if necessary.
Place the watermelon cubes into a blender with the juice of half a lime and blend until smooth and frothy, about 30 seconds. Strain the mixture through a fine sieve into a bowl to remove pulp if desired.
Pour the strained watermelon juice into a cocktail shaker. Add the tequila and a handful of ice cubes.
Shake vigorously for about 15 seconds until well chilled and combined, hearing the ice rattle inside.
Prepare glasses by rimming the edges with lime juice and dipping them into salt on a rimming plate. Fill each glass with ice and strain the cocktail into the glasses.
Garnish with lime wedges if desired and serve immediately, enjoying the vibrant color and refreshing aroma.
