Scoop out the flesh from a sweet watermelon and measure out roughly three cups of it.
Transfer all the ingredients, apart from the limes, to a blender and blend on high until smooth.
Pour into 2 glasses, squeeze a lime into each glass and leave the lime skin inside the glass to serve.
Serve the Very Berry Summer Smoothie with a couple of ice cubes or use frozen berries as ice cubes. They will chill your drink, soak up the flavours and will be an exciting surprise at the end.