I don't fish much or plan to, but I'd like to have a depth finder in my boat just because I'm curious how deep the lake is in some parts where we go. I don't know anything about depth finders. All I know is that I don't want to drill any new holes in the boat hull and I need something as AFFORDABLE as possible (cheap is a nasty word). I use the boat really just for wakeboarding/waterskiing. I looked around on e-bay and saw some used Hummingbird 400 units for around the 50-60 dollar range, but I don't know if this will work for me or if they are reliable/accurate, etc. I need some advice!