http://www.endless.com/crocs-P.....ands=crocs

I know crocs are a no-no, but are the ballet flats acceptable? I am looking for a waterproof shoe to wear to Chicago. I have a feeling it is going to be raining at some point. I was told to look at Wellies. Is that an actual brand of shoe or just a nickname? So what do you all think of this shoe? Should I keep looking? Any more suggestions? Thanks!