Just after midnight, patrolmen of the Harbor Police spot two men pushing off in a small skiff from South Street wharf. Following them to the lower end of Smith Island. The officers confront them as they transfer their cargo of lead ballast into a submarine. Suspicious of any unusual activity so near the Philadelphia Navy Yard, the police arrest the supposed saboteurs and tow their “iron pet” to the Noble Street pier.

Word of the capture spreads like wildfire through a city already suffering from war jitters. Rumors spread as thousands gather at the dock in hopes of being allowed a look inside the “infernal machine.” Only a single reporter is given such opportunity; his sketch and description raise more questions than they answer. The two crewmen tell the police the boat is the invention of a Frenchman, Brutus de Villeroi, who has tested it along the river for the past two years—and wishes to donate it to his adopted country in her hour of need.

Up to this date, the U.S. Navy has shown no interest in submarines, which are yet to prove effective. But these are desperate times and, while the plan to defeat the rebel ironclad known to be under construction in Norfolk is to fight fire with fire, perhaps the strange vessel is worth a look. The commandant of the Navy Yard tasks a trio of officers to evaluate its potential.

Their report of 7 July 1861 is critical, but the construction of a larger, more powerful model might remedy the shortcomings they cite. Design and construction begin immediately and, a year later, result in the deployment of Alligator, the first submarine in the Navy of the United States.

In 2003, the Navy went looking for its lost sub where she went down in 1863 off the coast of North Carolina. To date, her remains have proven elusive—but what of the original boat first examined by those three naval officers?

His suggestion that the older boat be used for training rebuffed, and focused on building an improved submarine, de Villeroi tied her up along the creek that ran beside his workshop on the Jersey side of the Delaware. There she sat and slowly settled into the mud, outdated, unneeded, and forgotten by history. Until now.

While the main focus of “The Hunt for Alligator” was always on that vessel, parallel efforts on a smaller scale were also made to find the sub’s predecessor. Unlike the larger project, that devoted to what researchers dubbed “Alligator Junior” (due to her smaller size) were, and remain, a grass roots undertaking. Thanks to the dogged determination and incredible patience of Alice M. Smith, the local historian who has spearheaded the quest for the 1859 boat, there is a very promising chance that it has, in fact, been located. What is more, preliminary low-level aerial drone scans of the suspect area return indications that the original “fish boat” designed by de Villeroi in 1837 in France, and known to have been brought by him to the United States, may rest nearby.