Hippos Can’t Swim? | Natural World | BBC Earth https://www.youtube.com/watch?v=xu4T9kawhAM
And from wikipedia: https://en.wikipedia.org/wiki/Hippopotamus#Characteristics_a...
"Despite being semiaquatic and having webbed feet, an adult hippo is not a particularly good swimmer, nor can it float. It rarely enters deep water; when does, the animal moves by bouncing off the bottom."