I think if I were making that trip with a 6 ft draft, I would take Hawk channel all the way to Key West rather than trying to cross Florida Bay. If you decide to cross Fl bay, I would suggest daytime travel only with a good lookout, lots of shoals ( did anyone tell you about the fines for running aground and damaging the sea floor? ) , and lots of pot bouys.
All that is necessary for the triumph of evil is that good men do nothing. Edmund Burke