He's not going to be able to lift his arms to spin in a circle if a blue whale done landed on him. The impact has also likely knocked him out for a ten count.
And even leaping peak human style, leaping the full way out from a blue whale is a bit stretching it.
I'm increasingly coming around on Beast Boy for this. Between the verging on microscopic fly, the dragon thing (again, if valid), and whale from above, he has a variety of options here.