The Waterproof Swimmer, The Waterproof Coach and The Waterproof Triathlete are 100% waterproof. However, you will notice that when your book gets very wet and is then exposed to air, it tends to become a waterlogged brick.
Do not panic! This is normal. The pages will stick to each other; it’s called molecular attraction–or something like that.
If the book was exposed to chlorine or salt water, rinse it with fresh water. Then take your waterlogged brick and set it by a fan. Separate the pages and gradually the book will dry. Once dry, the book will be back to its old happy self.
You’ll also notice that as long as the book is completely immersed in water, the pages are easy to turn. (And it floats, too!)
It you don’t want to deal with drying the book, put it in a plastic bag. Of course, what’s the point of a waterproof book if you have to put it in a plastic bag?