I've dove a set of natural rocks/ledges in Destin. I can't remember the name of it, but it was maybe 4-6 miles out. (close enough that ScubaTech would run to it).
While it wasn't super exciting as some of the tropical locations, it was a good dive site....
I'll see if I can look it up when I get home and figure out the name.
Most likely what you dove was either Anchor Rock or White Hill Reef. Both of these are in the vicinity of the Destin Liberty ship and are often done as a one, two drop.
White Hill:
30-19.017 086-34.990
Anchor Rock(s):
30-18.856 086-36.244
30-18.801 086-36.122
Shark Alley (vicinity of the BR):
30-20.914 086-28.435
Dive at your own risk, I take no responsibility for accuracy of my marks.
N