Just watched Planet Earth, a BBC's HD TV program. The film is nice, at least in terms of picture quality. The first episode features, amongst other things, the journey of elephants in the middle Africa where rain causes lots of flood. The elephant has to walk pass the uprising lake and they took the camera under the water to record elephants in the water.
It is my first time knowing that an elephant can swim. Just like a hippo, it seems that the elephant itself floats in the water. They can do something like walking in the water and they actually move. It is amazing to see such a big land creature floating in the water.
Try it if you have a chance.