The only certainty in fishing is that you cannot buy your way to success. Side scanning may be a good thing. I'd never criticize new technology. But it is certainly not a necessity as some would have you believe. A simple 2D black & white unit (like we have) will clue you into what is going on, just as well as a $2K unit you can get at Cabelas these days. Those expensive units are nice, no disputing that, but not necessary to success. Just my $.02!
"A voyage in search of knowledge need never abandon the spirit of adventure."