I, too, have a simple fish finder. It's a Humminbird 565. It doesn't have color or any of the other fancy features, but it shows the bottom contour. It also has a feature that shows a little fish symbol on the screen when it detects fish. How reliable is that feature? Would other things, like a twig or stick or whatever fool it into thinking that there is a fish? You can turn that feature off, and fish are then indicated by a eyebrow shaped curved line on the screen. So which is better? The fish symbol or just the curved lines to indicate fish? Or does it make any difference?

Thanks

GF