Do underwater Iphone cases work?

I'm thinking of going to buy an underwater IPhone case. The brand name is Coco fun water-protection. It looks like a life proof case except the brand name life proof isn't on the case. Would you recommend getting this case and do you think this case will work?

Hell yea its awesome

I think your phone won't work underwater and you are just getting a waterproof case for your phone. You could just use a zipper bag to protect it if you are going boating. Blow air into the bag so the phone floats if it goes overboard. Put a yellow, orange or bright color paper inside the a bag so you can see if it goes overboard. Blow it up slightly and check that it doesn't leak before you use it.