Swim diapers are not waterproof.
They are manufactured without the SAP (super-absorbant polymer) that makes most modern diapers swell up and hold a lot of liquid.
A super absorbant diaper would become very large and heavy if worn while swimming.
While alot of people assumed that a swim diapers are absorbent and contain urine like a regular diaper, they do not. The purpose of a swim diaper is only to contain solid waste. With a snug fit in the legs and waist (which is key to proper function) the fiber lining encourages the solid waste to cling to the fiber, but is doesn't have an absorbency layer.
It depends on the type of diaper - there are disposable and reusable/washable/cloth swim diapers. As you can guess by the names you can reuse the reusable swim diapers - you need to wash it with hot water and dry it in the dryer or outside in the line. The disposable swim diapers are meant for a single usage only. Even if your child has not peed or pooed in it you should toss it because it will not contain the next time you use it - it won't fit snug again. This is the reason why I chose reusable swim diapers for my kids and I recommend them to everyone.
Swim nappies can be bought in your local Walmart or Target. Pampers and Huggies each make a swim nappy. One can also purchase reusable cloth swim nappies.
They are just as good. They don't swell up and hold in water like most throw away swim diapers.
"Huggies overnight diapers should work better than daytime diapers, since they are designed more for longer wear and more durability. Hope that helps.."
There are some bathing suits for babies that are made with diapers in them. Also, there are diapers made just for swimming. There are many brands available one of them are called Huggies Little Swimmers.
The largest size for Little Swimmers states from 32 pounds up. If the teen is of a very slight build, this may work. If the teen is larger, there are adult swim diapers available for purchase.
From experience
Yes -- the material is stretchy enough to work with either disposable or cloth diapers.
Yes third graders can where diapers in fact i wore diapers sense third grade myself. its a nerve in your brain that doesn't work well
Dog diaper pads are fairly descriptive - they are used as diapers for dogs. They work in the same manner that baby or adult diapers work. They also come in various sizes.
they swim
Immersed in it!