Note from Karen: The important thing to know about all washable, reusable swim diapers is that they are designed to contain poop. They are not thick diapers and are not designed to do much at all about pee. They are just for soil containment. This has some light padding, but don't expect a full pee-flood to be contained fully in the car seat in a swim diaper. Use a diaper when a diaper is needed. A swim diaper is not the same thing as a diaper and it not the same thing as a diaper cover. The fit is different. Proper swim diapers fit snugly. They will not allow a big air bubble to form inside them and possibly tip baby's face down as the air rides up, which is scary. The snugger shape of the swim diaper means they don't fill up with a big puddle of heavy water when you lift baby out of the water, either. A swim diaper that fits properly shouldn't be very saggy but should fit reasonably snug to the body. We do not suggest using diaper covers as swim diapers. Choose a real swim diaper for swimming.