Molasses Reef is one of the most popular dive and snorkel sites in the Key Largo Marine Sanctuary. And with good reason. This beautiful reef usually has very good visibility and the marine life is mostly undisturbed and abundant. The reef is marked by a 45 foot tall steel light tower and has 33 mooring buoys marked M1-M33. All except for 21-23 are shallow dives and snorkeling areas. 21-23 are a bit deeper for diving only. This site was named after a barge carrying a load of molasses barrels grounded here many years ago.
This reef is a well-defined spur and groove system that stretches out from very shallow waters to about 40 feet. The buoys closest to the tower are the very shallow dive sites and snorkel sites. Hard as well as soft corals rise up from the sandy bottom. A large variety of rope sponges and vase sponges cover the substrate in the shallow area and helps to give the reef its incredible colors.
Then as the buoys extend outward, the reef gradually becomes deeper. Large barrel sponges and tube sponges can be found at around 30 feet deep.
The South end of the reef is known as "The Aquarium". Some of the largest schools of fish in the Florida Keys can be found in this area. Horse-eyed jacks, permit jacks, bar jacks, yellow goatfish, small-mouth grunts, sergeant majors, angelfish, parrot fish, blue tangs, barracuda, grouper, and very large tarpon are often seen in the area. But don't get me wrong, these fish are all over Molasses reef!
You'll probably see a few nurse sharks, moray eels, lobsters, turtles, crabs, sting rays and even spotted eagle rays and manta rays on this reef, too.
An eight-foot Spanish anchor lies in the shallow waters near M3. No one knows the history of this anchor.
"The Winch Hole" is near M8. It is said that this winch belonged to the Slobodana, a 176 foot wooden schooner that ran aground on Molasses Reef in 1887. It now lies scattered on the ocean floor. Southwest of M8 there is a coral ledge with a hole large enough to swim through. This is called "The Hole in the Wall".
At the M11 and M12 buoys is the area where one of the worst groundings at Molasses Reef happened when the M/V Wellwood that ran high aground on this reef. The 400-foot (122 meters) freighter completely pulverized several very large star coral formations.