I often wish humans had descended from fish instead of apes. A lot of the worlds’ pollution would be eliminated if we could just dig canals and swim to work or school instead of paving roads for cars. We wouldn’t have to get haircuts, because fish don’t have hair. We wouldn’t have to build aircraft to fly over the ocean; we could visit our island friends anytime we wanted on our own power. The only real downside I can see is that we wouldn’t be able to eat tuna fish sandwiches.
As it is, the feature that brings us closest to fish is the webbing between our fingers and toes. I don’t know of a plastic surgeon who can increase the size of that webbing, but I bet it would be a useful procedure. Think of how easy it would be to scoop water with your hands if you had extra webbing.