not sure if this is a stupid question or not. does a non-swimming 4 year old need armbands in a swimming pool where the water only comes up to their chest? other than that what "rules" would you have for someone other than you (in this case a nanny) taking your los swimming - esp in a crowded open air pool. 6 year old dd can swim about 5-6 metres. both have had lots of lessons but 4 year old not ready to go without floats yet. along with roads swimming pools worry me - (not much else does) no-one can be as vigilant as yourself can they?