It is actually waterproof, unlike the last one I bought which claimed the same thing. And a plus I wasn't expecting- the hem is a bit heavier which helps to keep it from flying up (I have a plastic tub so magnets and suction cups will not work). It is weighted at the corners, but I don't remember with what- though I think it said in the product description. It does still fly up just a tiny bit in the middle, but its much better than any I've had before. It's only been up for a week, so I haven'tSee full review