That's a big fat NOPE from me. Not only is it irresponsible on the supervising adult's part, but unfair to dump the responsibility of essentially babysitting someone else's kids on complete strangers.
I also think it's a little outrageous that it's "okay" rule-wise for unsupervised 8 year olds to hang out at a public(ish) pool! I think it's 13 or 14 at our pool and you have to pass a swim test first.
4951