The old, decrepit Port Mayacca Railway Bridge has long been a thorn in the side of sailors who want to make use of the Okeechobee Waterway. With its official 49 foot or so (see below) vertical clearance, it is clearly a limiting factor. Of course, nearby Indiantown Marina has achieved a bit of a cottage industry by, with prior arrangement, meeting sailcraft short of the bridge, lashing on plastic water jugs and creating enough artificial heel to get a sailboat with a mast just over 49 feet, under the bridge. Of course, as you will read below. some undertake this task for themselves.

Claiborne,
This is an update to your very appropriate warning concerning the railroad bridge to the east of the lock on the east side of Lake Okeechobe. To remind you, I have a C&C 34 with a listed mast height of 48' 6" and the railroad bridge, a lift bridge, has a charted clearance of 49'.  The website for the Army Corp of Engineers, Jacksonville showed the clearance at 49.7 for the period in question, but it fluctuates with the level of the lake.
The lock was open when I crossed.  About 10 days ago I approached the bridge, after hanging 4-6 gallon water containers from my boom which I extended over the port side of the boat.  I also piled all sails, anchors, chain and other misc. heavy items on the port rail.  As you suggested I inched forward at the slowest speed posible and passed under the bridge with only my radio antenae touching the steel beam.  A fellow boater who had proceeded ahead of me was watching from the anchorage by the lock and kept me advised as to space between my mast and the bridge. His encouragement was a great help. The weight on my boom and port rail resulted in about a 10% lean which turned out to be sufficient.  A friend who was a former math teacher had calculated that a 15% lean would give me about 9" of space so my 10% lean was less than I wanted, but all is well as ends well.
The anchorage by the lock is adequate for about 3 boats and I had a fairly quiet night in about 8' of water, but the trawler on the west side of the anchorage dragged anchor when the cold front passed in the night with 40 knot winds.  They were able to set the anchor and ride out the wind safely. the next day brought a choppy crossing and 2 days later I reached ft myers.  i wanted to thank you for you advice, so thanks for the help.  it is appreciated.
Bruce Jarchow