For fishing definitely sonar for the reasons mentioned above, camera I think is good for two things: fun and thorough investigation of a known good spot, if you go on a new spot and start messing with camera, unless you are really lucky, you will most likely waste your day, I don't own camera and am not ready to pay the price yet, but I can't imagine fishing without sonar. Although if you come to the lake drill a random hole and stay on it all day, sipping bear and being happy, camera could suit you best.