Gerry, Actually you can step your mast on the Illinois River after mile 239.7 (southbound) for a clearance of 52' all the way to Mobile. However, 52' is the controlling clearnace at "normal pool". During periods of heavy rain the pool may go up 8, 10 or even 20 feet reducing the overhead clearance on fixed bridges accordingly. Putting the mast back up early places you at risk for (1) pool level increases and (2) opening bridges which are not functioning. For my money, if I took the mast down in Chicago, I would ship it to Mobile and enjoy the ride on the inland rivers. You would now be functioning as a small slow trawler with deep keel. Good luck on your trip south. Bob Skipper Bob Publications Http://SkipperBob.home.att.net