Christep,
Take a look at:
http://aviation-safety.net/database/1996/961123-0.htm
Ethiopian Airlines ditching in 1996 following a hijack.
There is also a book by two of the British survivors of this flight, "Hijack". And at the bottom of the linked page a link to some truely frightening video captured from the beach.
This shows that on ditching - survival odds, not good, but survivable - yes.
Never give up!