We're lucky -- my area has several nice pools, and the summer family rates are pretty reasonable, but I have friends with kids that live in different areas with nice pools, so we vary our summer pool visits between places when M is here, so we don't pony up for a family pass to any one pool.
And the closest pool, which is pretty nice, with a grown-ups only pool area adjacent to the kid pool, and water slides and a diving board separate pool, is not that crowded when it opens at 11, and M is old enough, and a good enough swimmer, that I can float in the grown-up pool on my raft and keep an eye on him in the nearby kid pool at the same time when we go to the pool by ourselves.
And when I go with a girfriend and their kids, the kids entertain themselves and we can float for a while after playing with the kids for a while, then one of us can run and do a round up if we see 'em running off to the waterslide without asking permission, which they rarely do, since they're good kids.
When I was 10, my sister and I spent the whole day at the pool without adult supervision, but I am a little more paranoid, since our pool was an apartment complex pool, and this is a big public pool. I'd like a waterproof GPS to attach to his swim trunks, actually. Is that too much to ask?
M thinks he knows how to swim, but he can just dog paddle from the diving board to the side, only when I dive first and wait for him at the side, so we are definitely getting him swimming lessons this summer. I am a good swimmer, and I try to teach him, but when we're at the pool together, all he wants to do is play, and I get that. So -- lessons with someone else.