James, I have a HB Piranha 170 (about $100) in my Kayak (and had it in other boats before the Kayak) and it does all I need (depth, Fish ID, structure). Sure, there's a lot better ones out there, but with a higher price tag. There's a Board (on this site) specifically for FF's, so it might provide you more info. I'd just say buy the best you can while staying within your budget.