One thing that was mentioned during a radio interview is that there are/were 80 unaccounted for vessels in Santa Rosa Sound. That means 80 more obstructions that could sink/dissable a powerboat, not to mention all the debris and chunks of roadway. For an emergency system that is already spread thin, one more yahoo on a sinking boat would be a problem. Also, I am sure there are significant changes to the waterway that are unknown at this time (read as: more sandbars to run into).