Abandoned submersibles are not uncommon in the world’s oceans, but one as old as the Sub Marine Explorer certainly is. Explorer was built between 1863 and 1866 in Brooklyn, New York for the Pacific Pearl Company. But problems with decompression sickness and overfishing of the pearl beds saw the vessel abandoned in Panama in 1869. Well known to locals but presumed to be a wartime wreck, Sub Marine Explorer was rediscovered by archaeologist James P. Delgado in 2001. It has since been the subject of two documentaries, one by National Geographic.