Archaeologist James Delgado, host of National Geographic International Television's "The Sea Hunters," which also features best-selling author Clive Cussler, has announced the discovery of a forgotten Civil War submarine, the Sub Marine Explorer, on a deserted island on Panama's Pacific coast. Delgado's account of the sub's history and discovery was announced at a recent press conference and is featured in his new book, Adventures of a Sea Hunter: In Search of Famous Shipwrecks (Vancouver: Douglas & McIntyre, 2004). News of the discovery comes as the U.S. Navy and the National Oceanic and Atmospheric Administration continue their search for the USS Alligator, the Navy's first submarine, which foundered off the North Carolina coast in 1863, and work continues to preserve and study the remains of the Confederate submarine H. L. Hunley in Charleston, South Carolina.
With interest in Civil War submarines at an all-time peak, Delgado's discovery highlights not only the role of subs in the Civil War but also the exploits of a forgotten New York inventor—whose invention may have killed him. His submarine was the most technologically advanced craft of its age, even more so than the fabled Hunley, but it had a fatal flaw. Its crew compartment, pressurized to the same intense pressures as the deep to allow divers to freely leave and reenter the sub to disarm enemy mines, lay explosives, or, in its final career, collect pearls from the seabed, did not allow the crew to "decompress" when the sub returned to the surface.
That meant the men inside were exposed to the dreaded "bends," which can cripple and kill divers. History records that the first American victims of the bends, also known as decompression sickness, were workers laboring to build the Brooklyn Bridge in 1869. Descending to the bottom of the river in pressurized caissons, they were struck with a debilitating illness that mystified doctors, who termed it "caisson disease." It was not until decades later that researchers discovered the cause: rapid decompression after spending time under pressure. The first American to die of caisson disease is said to have been a worker on the St. Louis Bridge in 1870. But Julius Kroehl, a former Union naval officer and inventor of the Sub Marine Explorer, died in Panama of "fever" after several test dives in his craft in 1867. Physicians who have reviewed the technical details of the Explorer and her dives have determined that Kroehl suffered from decompression sickness, which has similar symptoms to malaria, also called fever. It is likely that Kroehl, in fact, was the first American to die from decompression sickness, which continues to claim the lives of divers each year.
A German immigrant and a resident of both New York City and Washington, D.C., Kroehl built the Explorer in Brooklyn between 1863 and 1865. The submarine was abandoned off Isla San Telmo in Panama's Pearl Islands in the fall of 1869, after its final crew was stricken, to a man, with "fever." Laid up and forgotten in a small cove, it remained unidentified until resident fishermen on a nearby island pointed it out to Delgado, who was sailing through the islands in 2001. "They thought it was a Japanese midget submarine from World War II," recalls Delgado. "It turned out to be much older and much more significant. In this case, truth is stranger than fiction—although it feels like finding Captain Nemo's lost sub on Robinson Crusoe's island." Delgado led an expedition to Panama earlier this year with the Sea Hunters crew that included a representative of the Historic American Engineering Survey and Hunley Project Historian Mark K. Ragan to document the sub and remove the sand that clogged her interior. They found intact glass instruments filled with mercury and the intricate pipes and valves that controlled Kroehl's Explorer.
Plans are under way to continue the documentation of the Explorer and perhaps bring the submarine home. Where she might go is up for discussion. One option is the foot of East Third Street in Brooklyn, where she made her first dive. Another is the Warren Lasch Center in Charleston, where the H. L. Hunley is undergoing conservation for eventual display. A third possibility is Washington, D.C., home of Kroehl's wife and site of the family home, when Kroehl was not working as an inventor or in the Union Navy as an underwater explosives expert attached to the staff of venerated Admiral David Dixon Porter.
Editor's Note: Delgado will be detailing his team's findings in a keynote address to the Seventh Maritime Heritage Conference at the Sheraton Waterside Hotel in Norfolk, Virginia, on 29 October. For details, visit the conference Web site, www.nauticus.org.