Just a heads up, iPhone’s are not waterproof. They are considered water resistant. I work on them and I always tell people don’t take them near water and get a camera like a gopro for activities like that. I would recommend taking your phone to a repair shop, well know shop I should say. Rice does not remove water from electronics. The water stays in there and creates corrosion. Phone has to be taken apart to dry out or cleaned properly. In your case, your screen might be damage and need to replace since the water got between the layers of the lcd and created a problem and since the phone still works it can be saved. Just don’t wait too long before its too late.