I have side scan and down scan on our Lowrance HDS gen 3, 7 inch screen, side scan is great for lake fishing for spotting which side of the boat the fish are on, also shows details on structure on bottom. It's really good to see in detail what is under the boat or off the side.I don't think side scan will be much good at showing salmon in rivers off to the side. Might want to check out Panopix, spendy but 360 degrees.