Side imaging definitely will not be use less in an 8 foot deep river. Although i realize that this isn't deep what about scanning when idling up or down river & finding a huge school that you wouldn't have saw otherwise? It's also good for finding brush piles, rock piles etc. I have side & down imaging at the console & trolling motor both & wouldn't have it any other way. Humminbird units are pretty easy to maneuver through. I wouldn't hesitate to buy one if i were you & if you get another boat you can also move it to it. I have an old humminbird 798 ci si that is loaded with hours at the console that i've had on an old sprint boat, an h-56 Xpress, a Dyna Trak 180 STE & now i have it on my 2003 Stratos 18XL that i've had for almost 6 years. This 798 has a bunch of hours on it, but it's been flawless. I use it for running, but do use it for scanning for bait & fish. Works real good when striper fishing in spring at night. I run a helix 9 up front & split screen 2d, down imaging & maps sometimes too. I absolutely wouldn't hesitate to purchase the unit i was interested in. They'll do so much more then tell depth & water temps.