TIL In Crysis you can be eaten by a shark.

Close to the beginning of the game, when the sun first rises, I was trying to see if there was a limit to how far into the ocean you can go. The boat stops after a while, but you can swim for a decent amount of time. Heading in what I presume to be west, you can enjoy some nice coral formations in shallow water, and then you reach a raised area on which you can stand. At that point you hear prophet warn you that these are shark infested waters. If you leave the raised area to go further out, the water becomes difficult to see through and there is no visible bottom. You can swim for a little while longer until a shark literally comes out of the blue and eats you.

And you die.

EDIT:

Example 1: A rather poorly recorded example I made - http://www.youtube.com/watch?v=ZAOBOV6d7gs&feature=youtu.be

Example 2: Someone else's example - http://www.youtube.com/watch?v=9Lh0MlTM5KM