I have the wristwatch model myself and have found that it's best used as a tool to scout areas out before you fish them. Once you're familiar with a particular area, you'll begin to be able to tell what kind of fish are holding in that area when you find them using the finder. In all, it will tell you if the fish are there, but it's up to you to figure out how to land them. It's not real effective for just casting out and using it for real time data, you'll just end up tangling your lines. There was a whole discussion on this in the tackle forum.