You dont have to escort them back. Cripple every ship in the flotilla and allow the True King of Justice escort them to where He sees fit. Even "re-directing" them will send a message of ambivalence and encourage more of these theatrics.
Justice Ministry: Information examined by AG about Gal Hirsch didn't come from police (Haaretz)
from the article: Netanyahu: Israel will not allow flotilla to breach Gaza naval blockade