1956 vs this version

I enjoyed the original version and saw it years and years ago. I have just seen this one. While this one was not bad, I still preferred the original.
However my point is about the actual whale.
Just looking at some clips of the original now on You Tube it makes me think.
How come in the original, which was made 56 years ago, the whale actually looked more real and life like then this one did and here we are in the modern age of CGI, computers, animation etc etc.
Does it show just how good they were with special effects back in the day without all the help they get these days?