I just received this in the mail today.  I had bought another swim diaper from another company as well.

When I opened this, I first noticed that there is nothing inside of this diaper but a thin, cloth lining like you would find in a bathing suit.  The swim diaper from the other company has lining as well, but also padding to absorb urine.  I was confused by the description that public pools require a reusable swim diaper blah blah blah since this will not hold urine .  I put water in the diaper and the water just pooled; if there were a body in the diaper, the liquid would displace.  The shell is water proof, so it didn't leak through the fabric, but realistically, it won't just sit between the lining and my child's skin.  Common sense tells me the liquid will escape through the legs when a child is in the diaper.  I imagine that it would hold solid feces, but nothing liquidy or loose.

I might use this in the ocean or gulf, but not in a pool or while my baby is playing in the sand.