9 cups cubed seedless watermelon (about 1/2 a watermelon)
1/2 cup fresh lime juice (from about 3 limes)
1/4 cup simple syrup (or to taste)

In a blender, puree the watermelon chunks until they’re smooth and liquidy (you might need to do this in batches, depending on how large your blender is). Set a colander over a bowl or a pitcher and strain watermelon puree, discarding pulp and any seeds. Stir in the lime juice, and stir in simple syrup to taste. Serve chilled, over ice, with a lime wedge for a garnish.