Probably should clarify when I said scraped trying Destin I was talking about mast tip not the VHF.
Under calm conditions with opposing current
and a helper up on the bow you can creep up to a bridge with little danger
to the rig.
On heeling over using external ballast, take a look at the geometry. A lot of heel for a small reduction at near vertical angles. I was talking to a sailmaker
years ago that had built a bag similar to that video. The FMP saw him slipping under Brooks Bridge all heeled over and told him they would ticket him for dangerous operation of a boat if they ever saw him try it again.
One time with a unusually high tide at Brooks I lashed my buddy's 27' sail boat along side and hooked my main halyard
to his far side Spring Line Cleat. Winched until I was afraid something was going to let go and under we went. FMP would have loved that stunt.
Based on my memory, Dupont would be a good start as I think we often cleared with the VHF not touching, Brooks would be second, and I don't think you will clear the center at Navarre but the increased clearance to the side is real. I tore off my windex proving that point trying the center of Navarre after we had easily cleared the side path.
Winter low tides will also give you some more margin for getting a feel of things.
As I said before the VHF will be your gauge, and keep some notes on the water level against the fender
boards. It took me some anxious trips before I finally worked it all out and we had two more 50 ft (nominal) bridges back then. We found the posted clearances usually are a little lower than actual.