Theoretical wave height cannot exceed the depth of the water. i.e. you cannot get 6 foot waves in 5 foot of water. What happens is they "break" and technically, they aren't "waves" anymore and don't follow the same rules. The big problem is that they still have MASSES of moving water being delivered in a certain direction. Very large things move when cubic yards of water hit. No offence to the bridge in Pensacola, but there are cases of 100-200 ton solid blocks of shorebreak stone being displaced in storms. That bridge span was no big deal to move. Also the normal depth of the water is added to by storm "surge" ahead of Hurricanes ; water is pushed and (sort of) "piled up" on the right/front quadrant of a storm. Now the wave height can increase even more because it is happening in water that is deeper. Last...the area of Florida coast you're looking at is relatively deep right up to shore, and the huge waves that have been pushed and have been building up all the way from the Western Bahamas have had nothing to stop them until they "feel" the bottom right at the Florida coast. By then, it's too late ... that water has to go somewhere. BTW ... OFFSHORE ... wave height, by itself, is not usually a huge problem. Given the choice between 10 foot waves 50 feet apart (crest-to-crest) and 20 foot waves 200 yards apart, I know what I'd rather sail in. Hope that helps some.
If you want/need more ... check out Adlard Coles "Heavy Weather Sailing", Van Dorn's "Oceanography & Seamanship", or a copy of "The American Practical Navigator" aka "Bowditch" Stay safe