From the website..
"**HERSHEYPARK suggests that that if you plan on riding rides to please bring into the park only items that can be safely secured in cargo pockets, a waist pack or a zipping jacket pocket. To secure loose articles, a cargo pocket must fasten with a velcro or button flap or a zipper, a waist pack should fasten around the waist and have a zipper closure, and a jacket pocket must have a zipper closure.
Due to the dynamics of some of our rides, loose articles are not permitted on most rides and should be left with non-riders or secured in lockers. Loose or hand-held articles include but are not limited to cameras, cell phones, pagers, purses, stuffed animals, basketballs, prizes, radios, hats, loose fitting jewelry, glasses, backpacks, ect. Hersheypark and its employees are not responsible for lost or stolen items which include items that fall out of pockets."