Bridge clearance on the Gulf ICW is 73'. We have made the trip from Galveston bay east )once to the
Mississippi River then south, once to
Pensacola then south, once to the
west coast of Florida). Between
Texas and P'cola there is the 50' bridge at Navarre so you have to do an overnight (that's how we did it) on the outside between Mobile or west, I think, and P'cola. From
Panama City to St Joe (I think) was an short outside sail, and then from Ft Myers we sailed outside to somewhere in the Everglades. This was in a
MOrgan 416 with a 60' stick plus 3' antennas. We never had a problem anywhere. Also much of the
East Coast ICW (although not much in
Florida, we go outside there) and shortest bridge is the 64' Fairfield (I think) bridge in
North Carolina.
But to answer your question about the Leopard mast heights (although this thread is a year old or so), the 43 has an
East Coast ICW friendly mast at around 63'. We have known more than one cruiser who has done much/all of the east coast ICW in a Leopard 43. The 47 has a 70.4' or so mast. Although I don't know anyone who has done it, I assume it is Gulf ICW friendly but it takes you outside on the east coast.