Should I bring my phone to a water park in a waterproof case or use a locker?

Use a locker if you don’t need your phone while swimming—it costs $5–$10 and keeps everything safe. Waterproof cases can fail from sand or weak seams, so test yours first by submerging it with a paper towel inside. Also check venue rules, as some ban cameras even in cases. Lockers avoid that problem entirely.