Navigation is a skill that needs to be learned. There are courses you can and should take and there are devices that you should have with you. At a bare minimum, you should have a device with the navigation program “Navionics ” loaded on it. You will also require a GPS signal to locate yourself on the charts that are on it.    If you have an iDevice then a proper GPS receiver is not normally part of it and your location information is derived from 2 or 3 cell towers. Remember that I said that a significant portion of the river is not in range of cell towers, so this will make the Navionics program not work. There are a number of companies that supply wireless GPS receivers at a modest price that can provide that signal to your phone or tablet. Please note that some non apple devices do have GPS receivers in them.  https://www.amazon.ca/dp/B006M49G80/ref=as_li_tl?ie=UTF8&tag=ca-402-20&th=1