I've mentioned on a few posts how I much prefer going bagless now. Started trip before last and all last trip. Got tired of waiting in bag check lines, carrying bulky backpack around all day.. it was hot wearing it fully, or shifting it from shoulder to shoulder all day. Realized didn't need the majority of the stuff I was carrying, and having to dig through pack to find things when did need them.
Usually do a mid day break, so only going for a few hours at a time. I mean, when i'm at home and go out somewhere I don't need to load up a backpack full of stuff.
I can take couple dollar store ponchos, cell phone, wallet, eye glass case (to switch between normal and sun glasses), chap stick, eye drops, fuel rod charger, and a small tube of sunscreen in cargo shorts and not look like an overstuffed chipmunk. Yes, know a lot of womens clothes lack the capacity of mens for carrying stuff. But for me and my son that's all we really need for a few hours in a park.
Yes, I spend a few extra $'s buying water in the parks.. but much rather that than haul around bottles of water, they either get warm anyway or if you froze them they make everything wet with condensation.
Still take a pack to the water parks since usually take change of clothes.