If your a first timer, check out out John Pennekamp State Park, America’s very first underwater park, it was established in 1963, covers 178 nautical-square miles of coral reef, seagrass beds and mangrove swamps. One of Pennekamp’s most popular attractions is the "Christ of the Deep" statue, which is located at Key Largo Dry Rocks reef.
Six miles south off Key West is the massive 524-foot Hoyt S. Vandenberg, a former United States Air Force missile tracking ship that was sunk in 140 feet of water. Beautiful dive... Marathon has one of the Keys' most frequented wrecks, the Thunderbolt. It sits upright on the bottom in 115 feet of water, the Thunderbolt measures 180 plus feet long, and sports a beautiful array of colorful sponges, corals and hydroids. There is also a 500-pound Goliath grouper guarding the wreck :) . The Spiegel off Key Largo is probably the most popular wreck in the Keys. At the time of its sinking in 2002, the Spiegel Grove was the largest ship intentionally sunk as a coral reef for divers. Tons of marine life !