Our last cocker who was a tri-colour (blue roan and tan) didnt like the water at all until my step-dad helped her get her confidence up, even then it was a long road ... in the end she'd only swim in a particular lake that they'd take her to.
My cocker I have now is a gold roan, and when I first got her, she didnt know what water was except for drinking out of a bowl. But with plenty of encouragement, and some fun water toys including a floating raft for her to sit on to begin with she began to enjoy it. Then the following summer, she was diving under the water of her own accord to find rocks, drift wood, sticks etc.