This soup is lightly sweet with just a little bite of heat from the jalapeno. The combination of both blended and diced melon and cucumber, plus the blueberries, also give it a nice contrast in texture.
Put 6 cups watermelon, 1/2 of the cucumber, jalapeno pepper, and vinegar in a blender; blend until smooth. Pour gazpacho into a large bowl and stir remaining watermelon and cucumber into soup. Refrigerate until chilled, at least 30 minutes.
Divide gazpacho among 4 bowls and top each with blueberries.
Per Serving: 122 calories; protein 2.5g; carbohydrates 30.5g; fat 0.7g; sodium 4.4mg.