Then I wonder how cliffdiving can be as safe as it is :blink:.
I think it has to do with endurance, and also how you hit the water. If memory serves me right, cliff divers position their bodies with their arms and head downwards, their hands out in front of them. This kind of mimics the dive of some sea birds. Their hands take the brunt of the blow, but I think the way they're positioned helps their hands cut through the water with little problem, and the rest of the force hitting the body isn't as severe.
Sorry if that makes no sense. I heard about this before, but it was years ago, so I don't remember. Basically, what makes the difference is the way you dive. You can position yourself to reduce the amount of damage you'd receive.
For Ducky, it was damaging because what received the full force of the impact was her back and the back of her head. As I stated, this is like hitting solid ground, thus knocking her out. The damage, though, wasn't as bad as it could have been. She isn't that heavy. Smaller creatures can survive falls from much higher up. Basically, if you were the size of an ant, you could easily jump off a table to the ground, even if the table is now as tall as a skyscraper to you, and not get hurt.
Edit: I did read a bit on wiki, and it does support what I stated, that the hands going in first help reduce damage. Someone tried to dive with their hands at their sides, and they ended up hitting their head and got severely injured.
Thinking back, the real reason Sharptooth died was not because he couldn't swim, and it was not just the boulder. He's already heavy and he's falling down. Whether or not he hits water or the rocks, he'd still receive the same amount of force on this back. The bigger you are, the more mass you have, the more damage you get from falling, and the less of a fall you'd need to make before getting hurt. Mainly this means that the bigger you are, the more likely you'd get badly hurt from simply tripping or falling off a chair.
Sharptooth would have been hurt as he was already, but now a boulder that's probably as heavy as he is hits down on him just before he hits the water. That means he was hit with twice as much force as he would have, and it was mostly on his back. That force may have been enough to not only knock him out but damage his spinal cord. His brain may have been damaged too.
Ducky was falling with an object that, even though light, added some weight to her, but she is still quite small and light, so she didn't suffer the kind of damage Sharptooth did, at least not to the same degree. A little shaken after she wakes up, but not too worse for wear. If Sharptooth had survived and woken up, he'd probably be crippled, unable to move his legs well, leaving him either with a permanent limp or not being able to walk at all, and if his brain got damaged, his personality would have changed. He could easily have become dopey from that fall.
