The schematics of Alligator and frequent mention of divers on the crew make it plain that this was the submarine’s intended manner of attack. But was deploying a diver through the forward airlock the vessel’s only means of assault? Or even its most effective? Several letters from Samuel Eakins—and a single drawing in the National Archives—suggest it was not.

Following the refit of the vessel over the winter of 1862/1863—and only weeks before its fateful trip towards Charleston—Martin Thomas penned a letter to Joseph Smith. In this letter, he sought to correct the Navy’s “misapprehension as to what Mr. Eakins has stated with regard to [the] Submarine Boat.” Evidently Eakins had been ordered to demonstrate the capabilities of Alligator “without adequate notice, with such men as would volunteer from the rough laborers of the yard, with orders to submerge her when the men who were never in her before absolutely refused to be submerged.” Upon surfacing and being asked whether he would now be willing to “attempt an operation against Savannah or Charleston ,” he answered “somewhat shortly.” When asked by Assistant Secretary of the Navy Gustavus Fox if he himself would be able to exit the chin hatch to make an attack, Eakins replied “No,” and so was abruptly dismissed. As Thomas explained, however, Eakins had not fully explained his thinking.

According to Thomas, Eakins was willing to undertake any mission, even if he were assigned a fledgling crew—so long as he was allowed to operate the boat as he saw fit. As Thomas had Eakins explain in his letter,  

“I believe that Mr. de Villeroi contemplated as one mode of operating, employing divers to go out of the bottom of the boat, in which a compartment is expressly constructed, and had an Italian trained to do so, who did it before the Board of Naval Officers. I was not witness to those experiments and have had no means to train divers, being still without even a crew. But this was not proposed as the only means or even the best, but simply one mode of operating. I propose another, by getting under a vessel’s quarter and working through the man-hole above. I not only avoid the risk of accident to the diver, and work with more economy to the Gov’t, dispensing with them and reducing, with my new propeller, the crew from twenty to twelve men, but I propose to work myself, feeling more secure of success. The mode of accomplishing the object can be of no consequence if the result is gained; indeed the whole manner of operating should be left to the Superintendent’s discretion, who knows more about the boat and submarine operations than any not initiated.”  

This mode of attack is perhaps depicted in an 1865 drawing of a proposed submarine from an officer on the blockade off Alabama, shown in the illustration below:  

As can be seen from his photograph, Sam Eakins was not a small man—which the divers exiting Alligator had perforce to be. His answer to Fox’s question was not meant to indicate that he [Eakins] could not make an attack, but only that Sam would not be making any assault that required him to exit the chin hatch. It simply was not physically practical. But Eakins could fit in the upper hatch, and his description of this mode of attack matches the 1865 drawing very well.

How would this have worked, and would Eakins have had time to implement the idea in the two weeks between Schott’s letter  of 19 March 1862 and the journey to Charleston? The drawing seems to indicate a one-piece suit, probably of iron or brass, fitted to the hatch opening of the submarine. There is no seam shown between the body of the suit and the helmet, and the arms—because necessarily flexible, as suggested in the drawing—must have been inserted into watertight sleeves and gloves. An alternative approach would have been to fit the interior of the boat with a watertight compartment for the “diver” to stand in, clad in standard hard-hat diving rig; this does not seem to be what is shown in the illustration. Such an approach would also have involved much more labor and time to install a second watertight door and would have resulted in flooding the forward section of the crew compartment where the wheel was located. The solid metal suit seems the simpler option. The idea of a man working underwater while “wearing” the submarine was certainly not new. Lt Selfridge supposedly suggested it  as did the author of the 1865 plan. A similar idea was put forth by Brutus de Villeroi as far back as 1837 in a submarine he demonstrated for two Dutch naval officers, who sketched a plan  of the boat showing watertight ports for the a submariner to extend his arms through the hull and work outside the vessel. Had Brutus designed Alligator to also use this method, just as he had thought to again employ the oars that propelled his 1837 submarine?

There is at present no corroborating evidence for this work ever having been done to Alligator. Eakins makes plain that it is his preferred method of using the submarine, but how common and available solid-suit “submarine armor” was in Washington in early 1863 is unknown. If the work records of the Navy Yard there are found, they might indicate what was actually done to the sub in March of that year. Until then, this theory must remain only a theory—but one which seems to have been a favorite of her commander. The only facts are those contained in the letters: Eakins doesn't need a diver; he himself will make the attack through the main hatch; and Eakins is very confident of his success.