I think all you guys are missing the most fundamental flaw with this. Put all that **** about thick hide and deep sea trench aside for a moment and think about this.
IF the creature came from the deep sea, totally out of oblivion having never been seen before, then how the **** do you explain NOT just the creature itself BUT ALSO the lice living on it being able to breathe out of water? How do you explain it being able to handle the light up top when we all know that creatures from the deepest depths have very poor and sensistive sight or are blind. Is it supposed to be some humungous ****ing amphibian that's just never decided to surface until now?
It just doesn't really make sense to me that it came from the sea, or am I over-thinking this???
Now back to the thick hide and resilience, are you all forgetting this thing called 'concussion' which explosions create. It renders horrible damage to internal organs, in fact you can be killed by concussion outright without getting so much as a scratch from the bomb that caused it. I'd hate to think of the amount of concussion a 500lb or 1000lb bomb would cause. In the movie we see the creature catch 3 or 4 of these suckers along it's back and still remain alive, surely thick hide or not it would have sustained serious injuries there.