Tommy wants to know if he could waterproof a phone and bring it into the water and use it as a camera. Leo says that there are water resistant phones, but he'd have to really understand what that means. IP ratings will tell just how water resistant it is based on 30 minutes in 1 1/2 meter of water. But that's in ideal conditions, too.
GoPro cameras are much better for that because they have waterproof housings. There are waterproof/lifeproof cases, though. LifeProof is a popular one with the chatroom. iGill claims a depth of 130'. But at over $300, Leo says that GoPro is a far better solution.