I knew, of course, that a bobcat would swim if threatened but the remarkable thing about this video is that he was not under any kind of pressure, and chose to cross where the river formed a broad pool when he could have gone a short distance out of his way and bounded across without getting more ...

This trail camera footage from Oklahoma of a bobcat casually entering a river and swimming away should settle this question in anyone's mind:

http://www.youtube.com/watch?v=j9-TBpf_jJk