I bought these Kushies swim diapers in sizes S, M, and L to have for my baby as she grows. They are wonderful and very form fitting to the baby's body. They are easy to adjust, very very durable, and are great for saving money (instead of buying the disposable swim diapers). And lastly, it's great for the environment!!! I definitely recommend these.
They are not made to absorb accidents, but they are made to keep accidents out of the pool, FYI :)