R/v Thunderbolt

R/V Thunderbolt is an artificial-reef wreck off Marathon in the Florida Keys National Marine Sanctuary. The largely intact 189-foot former cable-laying vessel sits upright on a sand bottom and is prized for photo-worthy features such as a large cable-handling reel on the bow, twin propellers, a cut-away aft exposing the engine room, wide swim-through openings, and hull and superstructure encrusted with colorful soft corals and sponges. The site is accessed by boat, typically via a surface mooring buoy attached to the wreck’s bow, with divers descending the buoy line onto the wreck. Typical dive depths range from about 75 feet at the observation deck to roughly 120 feet at the lowest parts; visibility is generally good, often 50 to 100 feet, and water temperatures are warm year-round (often mid-70s to 80s °F). Light to moderate currents can occur, but the wreck’s long axis lies parallel to prevailing flow so divers are not usually swept off the wreck. Because it is deep and fully submerged, plan for reduced bottom time; potential narcosis at depth and the structural nature of the site mean it is recommended for advanced or wreck-certified divers only, and any penetration should be done with proper training. Sanctuary rules require use of the mooring buoy and prohibit anchoring. Built in 1942 as Major General Wallace F. Randolph, the vessel was cleaned of debris and deliberately scuttled in 1986 to create the Thunderbolt artificial reef. The 189-foot hull, forecastle deck, superstructure, prominent bow reel, and an exposed engine room at the stern remain notable features, and the wreck is part of the Florida Keys Wreck Trek.