I Hate the Public Pool! or Give Me Back My Goggles!

We have been spending a lot of time at the public pool. A. LOT. OF. TIME. The only day we didn't go this week was Thursday. Let me tell you something about our public pool: the weekday crowd is SOOOOOO much better than the weekend crowd!
On the week days, the parents are nice, the lifeguards are attentive, and although there are a few too many tweens and teens there sans parents, in general they are kept under control.
But on the weekends, ALL HELL BREAKS LOOSE.
First off, it's crowded. Like wall to wall kids, and NONE of them are supervised. The ones who are being supervised, are being supervised by idiots who don't care what the hell they do.
Take for instance the horrible child that was there for no more than 60 seconds and stole Girl's goggles. They were very distinct. They had a pink strap, purple hearts around the eyes and Ariel from The Little Mermaid in one corner. A girl picked them up from the side of the pool. Now I will say that she was a big girl. Older than Girl by several years, and very overweight. The goggles were too small for her by a long shot. When I asked her nicely about the goggles she lied to my face and said they were hers. Now one only had to see how freaking tiny those goggles were on that little girls head to know that they weren't hers. The eyes didn't even match up with her eyes.
Later during a lifeguard break the girl and her mom were sitting next to us so Mr. Hobbitfeet asked her if those were hers because our daughter lost hers. The girl shook her head, and after looking at her daughter for a minute, the mom looked at Mr. H. and lied "Oh no, she got those from her bag." Even though we knew she hadn't. But we couldn't prove it, having been too stupid to put Girl's name in them, and the girl wore them around her neck the rest of the day, not giving us a chance to take them back.
I know that they were maybe two dollars, but that is not what I cared about, the girl stole them, and her mother, who should have known better backed her up.
Another example of evil brats and inattentive parents was when I was sitting in the shallows of the splash pool with my 1 year-old step-niece who was happily gnawing a rubber fish that she had brought to the pool, a little boy (maybe two, with no parent in sight) took the fish right out of her hands. When I told him that it was hers and he needed to give it back, he whipped it at her, splashing her in the face and beginning an afternoon of crabbiness.
Also there were a couple of teenagers that kept swimming into the lap lanes cutting me off while I was doing laps, and the lifeguards did nothing. They were maybe fourteen and when I told them for the second time that the lanes were for laps, one of the little brats told me "yeah yeah we KNOW Bitch!" Maybe if I dunked her sorry butt then the lifeguard would have paid attention.
So, even though our kids had a bunch of fun, Mr. H. and I are trying to work out how to only go to the pool on weekdays, and leave the weekends to the assholes without getting out kids mad at us. Any suggestions?

P.S. I did have a lot of fun laughing at the teenage girls trying SO HARD to look sexy in bikinis (even if they were too big). While I took Girl to the bathroom, I saw this one girl who was wearing a string bikini top with boy's trunks and kept looking at herself in the mirror and saying stuff like "enuh (like a yummy noise)" and "Damn (like she was super-hot)" and grabbing her boobs and butt (which I'm not sure had sprouted yet). Or the 15-year-old wearing a bikini and flip flop platforms so high she couldn't walk and TOWERED over all the boys her age at the pool.