On Thu, 18 Dec 2008 07:35:14 -0800 (PST), "
wrote:

The lowest fixed bridge is 53 feet clearance

Actually not. The lowest is 49.38 ft, the railroad bridge just
east of Lake Okeechobee. There is a local service that will assist
with heeling taller masts over, up to about 55 feet or so. The
bridges at Cape Coral and Ft Myers are currently at about 54 ft
depending on the tide level.

Water levels are now good on the main route across the lake:

http://www.saj.usace.army.mil/h2o/reports/r-nav.txt