Sombrero Reef is a designated SPA area and is one of the more popular scuba diving and Florida Keys snorkeling destinations in Marathon. The area’s name is derived from the 142’ lighthouse which is located in the northern section of the SPA region.

It’s called the “Horseshoe“ located at Mile Marker 35 in Big Pine Key. It was an old quarry which the dugout coral was used to build the Overseas Highway. At about 30 ft/10m deep in the middle, there is an ambulance and a small boat. Divers and Snorkelers use the location during poor sea conditions.

50-90’ – Starting in a sand pit at 50’, follow the spur and groove coral structures to the drop off at 90’. Large coral structures with beautiful schools of grunts. Explore the west side of the pit where we frequently see a large school of Southern sennets, typically over 100 in the school.

45′ – Named after a former Key Dives captain, Cindy’s Corner is soft sand meets a spur-and-groove reef at 45’. Look in the sand for stingrays and blue parrots at the edge of the reef.

A short boat ride away, this site offers a lot to see in a relatively shallow area, perfect for the second dive after the first deeper one of the day.

Part of a double reef system offshore of the main Alligator Reef and separated by a wide sand channel. Depths can reach around 90 ft (30m) on the farther edges.

NW and SE of Cheeca Rocks, Alligator Reef Sanctuary Preservation Area (SPA) bridges the shallow reefs of the Upper Keys and the deeper reefs of the Middle Keys. This rectangular SPA is a small bank reef protecting a spur-and-groove system, reef crest, and a portion of the northeast rubble ridge.

18-25’ – This shallow sprawling reef is a great place to explore. Follow our guides to the best hot spots this reef has to offer. You will see beautiful schooling fish, sharks, several species of eels, turtles and more!

18-20′ – If coral is what you’re after, this reef is for you. This shallow patch has absolutely incredible stands of stony coral. Massive starlet coral, symmetrical brain coral, knobby brain coral, elliptical star coral. This site was named after our in-house coral doctor, Dr. Kylie Smit

An inshore patch reef system with a variety of hard and soft corals which attract a variety of marine life. The smallest Special Protected Area (SPA) in the Florida Keys NOAA system. No touch or take of any kind.