Monkey Doodlez swim nappies, how do they work?

DD has two Monkey Doodlez swim nappies. I can't wait to use them for her first trip to the beach over Christmas! But now I've gotten them out to have a bit of a look, and they're not like the cloth nappies I'm used to! I expected them to be different, but they're so thin!

Is this normal? Is there normally more to them? I do I need to use something with them? I realise a regular liner would be useless as it would just fill with water anyway, so is the idea behind a swim nappy to simply hold in any poop?

Thanks :)

all swim nappies are basically designed to keep poop in the nappy not in the pool!theres no absorbancy ro anything because the pool water would puff it up too much :) just chuck em on and off you go!

Excellent, thanks Skybie! Yeah I can imagine what a regular nappy would look like in the water, or even worse - what would happen to a sposie!