Begin by slicing the watermelon in half. Using a large spoon, scoop out the sweet, juicy flesh and transfer it to a blender. Discard the rind.

Blend the watermelon until smooth and fully pulverized, which should take less than a minute. For an added tang, squeeze the juice of one small lime into the blender and blend briefly to incorporate.

If your watermelon contains a lot of pulp or seeds, strain the mixture through a fine mesh sieve into a pitcher. Otherwise, you can directly pour the juice into glasses filled with ice.

Store any leftover juice in a covered container in the refrigerator for up to 4 days. Note that the juice will naturally separate as it sits, but you can easily stir it back together before serving.