The 350 A is a great model for me. This unit will allow you to see the difference in the hard and soft transition areas, Since river fish rarely suspend, the resolution on these units allows you to locate and see fish that are tight to the bottom. Vertical jigging is very popular, and the key to fishing a jig vertically in current, is boat control. Work these areas over with a controlled drift. Use as much as 24 inch upward sweep of the road tip to rocket them upward, then follow them back down on a semi taunt line to detect strikes on the fall.
Blades wobble best on the upward surge, spoons better on the downward flutter.
And in rivers, spoons and blades typically offer fewer casting applications than jigs, their treble hooks are prone to snag when cast. Shoreline structures spout abundant rocks and wood, and even the bottoms of holes collect bits of wood that grab trebles. Stick to vertical jigging with spoons and blades in most current conditions. Another structural element that I key on, are the wing dams. In most the Mississippi there are several wing dams either near the tail water area or down river from the dam, When fishing a wing dam, I concentrate on the up current side of each wing dam or the flats between them.