I've been using my around the neck water wallet for five years at various different water parks. (My DS loves water parks. We've been to Schlitterbahn in Texas, White Water near Atlanta, Typhoon Lagoon, Blizzard Beach. His goal is to go to all the water parks on The Travel Channel's top 10 list. While that's not likely to happen, we go to lots of water parks.) Anyway, that water wallet has been through a lot and has never failed me. It has an adjustable clip that lets you adjust how loosely it hangs. I, too, tuck it into my suit when I am on a particularly rough ride. (Yes, he drags me on those!) I usually put my car key (only the one key that opens the car), my room key / charge card -- when I'm at WDW -- and a little cash -- $20 in it. I've seen bigger ones than mine, but I've never felt the need to have one. We don't bother with a locker. We take our towels, our water wallet, and one bag with sunscreen, water bottles, etc. in it. We dump our stuff as fast as we can and spend almost no time back at our chair.