Underwater Twins Bibb and Duane Mark 25 Years

For a quarter of a century, advanced and experienced divers have enjoyed diving twin "Treasury Class" 327-foot U.S. Coast Guard cutters off Key Largo. All the vessels in this class, referred to as "the 327s," were named after former secretaries of the United States Treasury Department.

The two cutters are the Duane and Bibb, longtime favorites among wreck, tech and specialty divers, that rest in nearly 130 feet of water one mile south of Molasses Reef. Considered the service's flagships, cutters served in a variety of capacities and gained notoriety as maritime workhorses for their battle with Germany's U-boats in the North Atlantic and the Mediterranean.

Commissioned Aug. 1, 1936, the Duane was named for William John Duane, the third Secretary of the Treasury, who served under Andrew Jackson. The vessel's lengthy service included escort and patrol duty in the Pacific, North Atlantic, support missions off the coast of Vietnam, flagship operations during Cuba's Mariel Boat Lift in 1980 and numerous drug busts in warm Caribbean and coastal waters during the 1980s.

Decommissioned Aug. 1, 1985, the Duane was sunk as an artificial reef Nov. 27, 1987. It sits upright in the sand 125 feet below the sea's surface.

One day later, Duane's sister cutter, the George M. Bibb, was sunk nearby. Named for George Motier Bibb, Secretary of the Treasury from 1844-45 under President John Tyler, the cutter Bibb served on active duty for nearly 50 years, from 1936 to 1985.

Bibb also performed numerous patrol duties during World War II in such ports as Pearl Harbor, Guam and Singapore, as well as customary peacetime jobs of search and rescue, and logistical support for the U.S. Navy.

Both serving more than 40 years, Duane and Bibb became two of the oldest active-duty cutters in the Coast Guard fleet.

Since becoming two of the Keys' most intriguing artificial reefs in 1987, the Duane and Bibb wrecks have attracted large pelagics and sizeable sea turtles. There's no shortage of big barracuda or the occasional manta ray or whale shark, especially in springtime migration patterns. Corals, gorgonians and basket sponges cloak the twins' decks.

Bibb rests on its starboard side, making for an interesting dive perspective from stern to bow with its crow's nest pointing sideways at approximately 85 feet. The port prop is reachable at 100 feet. Large schools of striped grunts and other reef fish species crowd in and out of the portholes near the fly bridge and other swim-throughs.

Both wrecks are recommended for advanced or specialty-trained divers due to their depths.

To learn more about Upper Keys artificial reefs, visit keylargowrecks.com.