Its construction was overseen by Lieutenant George Gordon Meade, then serving with the United States Army Corps of Topographical Engineers, and later as a general in the Union Army during the American Civil War. He forecast that the lighthouses would last for 200 years, and after 140 years, they are all still fully functional and in service. Its screw-pile design was an advanced innovation at the time. Large fingers of coral, rimmed with gorgonians and soft corals , are separated by narrow sandbeds. Colorful tropical fish like yellowtail snappers , blue parrotfish , squirrelfish or honeycomb cowfish are common residents here.
Lettuce corals lie under small schools of watchful barracuda .
The Arch is a popular coral limestone swimthrough. Nurse sharks and southern stingrays are often seen, as are schools of striped seargeant majors and bar jacks .