So I waltzed up to the lifeguard and asked him what their ploy was on bubs and swimming nappies as there was a young baby with nothing on. He said he would check with his supervisor. I went back in the water being careful to steer away from the mum and bub in question. Perhaps I wasn't discreet enough as the whole family got out of the pool shortly after even though they had t been there that long.
When I hopped out the lifeguard tracked me down and said apparently there are no guidelines. Although staff try to encourage parents to use swimmer nappies the parents can dress their kids in whatever they like. He did say it would be inconvenient to everyone if the pool had I be shut down due to an accident.
My response: "thanks for checking. Thankfully the family got out the pool before their baby did a big crap."