Swim Nappies, also called swim diapers or swimmies, are a special type of absorbent undergarment made for toddlers. Many public swimming facilities now require that infants or toddlers wear some kind of absorbent undergarment if the child is not toilet trained, so having a package on hand when visiting a public pool is a good idea. Using swim nappies at the beach is a good idea, because it provides the child with an added sense of security. They can worry less about having an accident and much more about swimming and having fun.

A regular nappy is made primarily of absorbent materials that grows as it absorbs liquid. Material in a swim nappy acts a lot more like a standard undergarment, allowing some liquid to pass through the fabric while trapping larger particles.

Another difference between swim nappies and normal nappies is that swim nappies come in smaller packages, which is probably a good thing because it is unlikely that parents need as many of these special nappies as they do normal nappies.

swim nappies are a bit more expensive than regular nappies. The main difference in cost is comparable to the difference between a basic nappy and an overnight nappy or training pant. Any specialized nappy product will cost more. However, swim nappies often go on sale, and can be found at discounted rates on a few sites, and experience reduced prices in non-summer seasons (however some stores do not maintain inventory outside of summer season).

Parents looking to save money may also search for reusable swim nappies. In addition to saving cash over the long term, these nappies are more comfortable (the material is much more like a normal bathing suit). Environmentally-conscious parents might also appreciate the reduced carbon footprint associated with a the reusable version.