You will be a motorboat until Mobile if you go the "normal" Tom Bigbee Waterway--bridge Clearance 50 feet (actually a little less in some places)--see: http://www.uscg.mil/hq/g-o/g-opt/Clearance.htm This gives clearance of most all of the U S Waterways! One friend of mine did the Tom Bigbeeway as far as Fulton MS--where one bridge was 49 feet and he needed 50+. The Mississippi shows a 55 foot bridge between Vicksburg and Cairo--so you might get it resteped at Vicksburg--but not sure of facilities there. Bob Austin