hello - this is probably discussed very often but I am looking on ebay for some swim nappies... I'd rather get re-useable ones but am a bit confused, my son is 5 months and we're planning to take him for his first swim soon. I have been reading about how various nappies 'catch' poo but I am breastfeeding and can't imagine his poo being catchable by a net liner! do i need to put him in a nappy plus a cover or will a good re-useable one be all i need? sorry if i sound thick!