Hippos perhaps mostly known to welter in the mud, not as speedy animals like cheetah or antelopes. On the other hand Hippo’s part of the big five in Africa and very dangerous animals. Check the video how fast the Hippo can swim in deep water, I was surprised to see that, how speedy that big animal is.
Speedy Hippo Video
You can check how speedy the Hippo can be in deeper water at below video.