This reef isn't 9 miles from shore or 9 miles from the inlet but somehow it's called 9 Mile Reef. It's more like 7 miles from the inlet and one of the closest well know natural reef.

N029.157333, W080.826083

9 Mile Ledge # (9N-90C3/V9M-90C4)
DD MM.MMM: 29°00.000', -080°41.000'
DD.DDDDDD: 29.157333°, -080.826083°
Descrption here.