Watermelon should be cut in half. Scoop pieces of juicy watermelon into the blender with a large spoon. Remove the rind and set aside.

Mix until the watermelon is completely crushed. This should take no longer than a minute. Squeeze the juice of one small lime into the blender and process for a few seconds for added flavor.

If your watermelon is very pulpy or seeded, strain the mixture into a pitcher using a fine mesh strainer. If not, simply pour it into glasses packed with ice. Watermelon juice can be stored in the refrigerator for up to 4 days, covered. With time, the juice will separate; mix it with a spoon to recombine.