Bob, I've been in and out of a few but not all of these places. I think that if you can plan your arrival or departures around the tides you will be OK with 4' draft and a single screw. The problem is that north winds blow all the water out and if you are unlucky enough to combine that with spring lows your draft will most assuredly exceed your depth. Crystal River is typical of many Big Bend rivers. It is about eight miles in (and back out) from the Gulf, which makes the day's travel a couple hours longer than you might think. Regards, Randy Pickelmann Morning Star lying Sunset Bay Marina-Stuart, Fl www.CruisingMorningStar.com Sent from my iPad