I have probably lost track of the original intent of the question about AC on the rivers - it seems a lot of folks are talking about "apps" by which I guess they are concerned with smart phones and iPads. Just to reassure myself, I fired up my 2011 version of Coastal Explorer on my laptop and centered the display on the Corps of Engineer chart for Demopolis. Then I hit "guide book" tab and sure enough, all the Active Captain balloons showed up. I like the bigger laptop display, but however you get your electronic charts to your face, AC is a good darned capability to ensure you have. Rich Gano Calypso (GB42 Hull # 295) Panama City area, FL