I was going to post some references for drownproofing classes, teaching babies to swim/float enough not to drown if they fall in a pool.
But then I found the American Academy of Pediatrics website, which recommends against teaching kids younger than 3 years old to swim. Seems like you can get lulled into complacency, and/or the kid can ingest so much water they get water intoxication. A study or two'd be nice.
And their recommended alternative, of course: enrolling in "a 'mommy-and-me' class" at the Y. Is there no end to this rampant motherism?
This is a controversial subject.
I remember spending a lot of time swimming round the pool with kids on my back. When they were ready they started to swim.
Parents can be too anxious for their children to achieve. If they have access to water they will want to play in it and eventually learn to swim.
When they are old enough to understand how it works, it is a good idea to teach them Drownproofing.
Non-swimmers (of any age)should not go near water unsupervised.