Platinum Pass logistics

I am most likely getting Platinum Passes for myself and my three t(w)eenage daughters for 2018. I generally wear a "waist purse" (fancy fanny pack) at parks, we travel very light and that does the trick. However, we would be visiting Cedar Point Shores, and I am wondering what the heck to do with the passes while we are watering. I can leave my phone and my keys in the car (the locks have a keypad), a credit card will survive the pools in a pocket, but what about the passes? I would be getting the meal/drink plans, otherwise I might get a handstamp and run them back to the car. Are they submergible waterproof? How large are they compared to a credit card? I could get some board shorts with pockets, but pockets on women's clothing usually leave much to be desired. I am guessing that a nylon fanny pack, though the height of fashion with a swimsuit, isn't going to be allowed on slides.

Also ... my real home park would be CP (closer to home), but we have a second home in southern Ohio that is closer to King's Island. I was thinking to use the "visit in 2017" to go to Winter fest. Would that mean we need to go to KI if there is an issue with the passes?

The passes are the same size as credit cards, and getting them wet won't be an issue.