The queen of the Marathon shipwreck fleet, Thunderbolt is endlessly fascinating to explore, both inside and out. Offshore, Marathon is surrounded by Sombrero Key and Coffins Patch, two no-take zones belonging to the Florida Keys National Marine Sanctuary, but it is Marathon’s most popular wreck, the Thunderbolt — which happens to be among the Florida Keys’ oldest — that attracts wreck aficionados.

Deliberately scuttled in 1986 as an artificial reef, 5.5 miles offshore, this 188-foot former WWII cable-laying ship has spent nearly three decades collecting growth. She sits at a depth of 120 feet, parallel to the current. Divers can’t get pushed off the vessel, nor does the flow hasten deterioration. Instead, this well-preserved gem sees ever-growing schools of amberjack, and, in summer, migrating tarpon. Year-round, it’s home to 700-pound goliath grouper and five-foot black grouper.

Structurally, the highlights of the Thunderbolt are the cable reel on the bow, and off the stern, two props. It’s a wreck where, thanks to hatches on the main deck and a hollowed-out superstructure, light penetration is allowed.

Yet, given its max depth of 120 feet, the Thunderbolt nets no more than 20 or 30 minutes of bottom time to divers with computers. The good news: If you’re looking to extend bottom time on shallower reefs and wrecks, Marathon’s menu of shallower wrecks and reef is 59 items long.

Marathon is located in the center of the Florida Keys, and is the hub of the Middle Keys. It’s got enough action to support six dive shops, yet it’s quaint enough that the dress code at its restaurants — mostly intimate — is flip-flops and board shorts. Plus, it packs big-time value. Marathon may lack the name recognition of Key West or Key Largo, yet delivers full-size grocery stores and other conveniences, such as several recently remodeled large hotels & resorts.

Become a Florida Keys Wreck Trekker!

The Thunderbolt is one of 12 wrecks in the Wreck Trek program. Click here for more details on how to dive them all.

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