2 1/2 cups seedless (or seeded) watermelon, cut into 1-inch cubes, rind discarded before measuring
3 tablespoons freshly squeezed lime juice (don't skimp on this)
4 ounces tequila
2 ounces orange flavored liqueur (I used orange flavored vodka)
1 1/2 cups ice
Lime wheel or watermelon wedge, for garnish
Put cut watermelon in a plastic bag and place in freezer for a minimum of 2 hours. (If time does not permit this step, add a few extra ice cubes when blending, the difference is not that significant.)
Stuff all ingredients into a blender and puree until smooth. Garnish rim of glass with a lime wheel or a watermelon wedge and serve immediately.