Might sound like a daft idea, but...
I love taking the kids swimming and I thought one way to carry on doing this when dc4 arrives is to put the baby in a sling. Ds1 and dd are 11 and 9 so independant in the water. Ds2 is just 4 and can swim almost 5m without armbands but still obviously very much needs me in the water with him.
I have done a quick googling and such slings do seem to exist but I can't actually find any for sale.
Anyone done this, or am I mad and will forget I have a baby on my front and end up dunking it? 