The CTA "River Line"?

Call it a crack-pot idea. Feel free to verbally abuse me for even suggesting it. But what do you think of having CTA ferries run along the South, North, and Main branches of the Chicago River? The Kennedy and Stevenson follow the general course of the North and South branches. Putting CTA "River Lines" would reinforce those travel corridors in the same way as the Blue and Red lines (the portions that run along the Kennedy and Dan Ryan, respectively). There would, of course, be no need to construct tracks, but only to create new stations. There might also be the possibility of T.O.D., but who knows for sure.>