Horseshoe Reef
When the wind has been calm for a day or two, the water clarity on the inside reefs improves. When the calm winds are accompanied by an influx of blue Gulf Stream water, the visibility increases dramatically. Under those circumstances, Horseshoe can be one of the top shallow dives or snorkel sites in the Keys. This is still a nice reef on any day, even if the visibility is reduced.
The depth is 8 to 10ft on the reef top, with a 22ft maximum in the sand on the seaward side. In spite of its name, the reef is a long bank of coral, featuring very large colonies of star, starlet and brain corals along the crest and branching corals on the back reef. A U-shaped sandy hole in the northern section of the reef, which is only apparent from a bird’s eye view, may account for the “horseshoe” appellation.
Slightly south of midway along the reef face, 6 to 10ft in from the sand, you’ll find the shaft of a large and very old anchor sticking out of the reef. It wears a thick beard of encrusting sponges and soft corals as a disguise, but you’ll spot it if you watch for the round shape of the ring at the top of the shaft. There are also curious blocks of pumice scattered along the sand in front of the reef, each a bit larger than a loaf of bread.
In addition to many other species of reef fish, Horseshoe hosts several schools of tiny silversides. During the summer months they swirl around beneath the coral ledges, sometimes in numbers so large they swell out into the open. You’ll see the dynamics of schooling behavior at work if you take a few moments to hang motionless in the water and watch predators like black jacks lace into the school. As the jacks zoom in, the school parts almost instantly. For fish in the middle of the pack, there really is safety in numbers.
Reproduced with permission from Diving & Snorkeling Florida Keys 2001 Lonely Plant Publications www.lonelyplanet.com