I bought a Splash Caddy a couple of weeks ago for the cruise I took last week. I bought the one that goes around your waist (as opposed to the one that goes around your neck), and it came with two waterproof "inner" bags that go inside the black outer bag. (But only use one inner bag at a time -- the other one is a replacement whenever the first bag gets a tear or whatever.)
I used it only once or twice during my trip, while snorkeling, and it worked just fine. I had cash and my room card in the bag and all stayed dry. However, I think that it might be difficult for you to fit a camera into the bag unless the camera is (1) small and (2) does not have sharp corners. If the camera is too large and/or has some sharp corners, it will probably rip the inner waterproof bag. Instead of taking this risk, you should consider buying a waterproof camera at the store. They can be purchased at drug stores, discount stores, etc. I think I paid about $6 or $7 for one. It seemed to work fine, although I haven't gotten the pictures developed yet.