Sink the Merrimack*
 

Initially, it was hoped that the submarine would be able to sink the Merrimack. Whether this would actually have been possible is a matter of debate. Certainly the diver would have had little chance of success were the rebel ironclad underway; Alligator would have had to attack while the enemy vessel was in dock. Its ability to do real damage would then have depended on the depth of the water. It must be remembered that Alligator was designed as a salvage boat; this is how it is described in the 1859 newspaper reports. Ships to be salvaged lie necessarily on the bottom, where the diver could easily be very effective. Villeroi had demonstrated his ability to deploy divers from his sub for several years, and underwater demolition was an established fact. But a floating vessel presents a challenge. Merrimack drew twenty-two feet of water--how deep was her mooring in Norfolk? Thirty feet? Forty? Limited as he was to the bed of the harbor by his "submarine armor" and the weight of the torpedo, Alligator's diver could not swim up to the hull of a vessel floating well over his head. But perhaps he would not have to.

An explosive planted on the bottom could be effective well beyond the immediate blast zone. Up to a point, the water surrounding the explosive would help: water cannot be compressed, and the explosion would have forced the liquid around the center outwards in an expanding "bubble" of water  This could have crushed in the hull of the Merrimack, which was not armored. That this could work was demonstrated by the Confederates in an episode reported by a Union spy. In September 1861, Mrs E.H. Baker--a Pinkerton operative--witnessed the demonstration of a Confederate submarine designed by William Cheeney. This boat used an airlock and diver (just like Alligator) to blow up a target barge tied up at Richmond. Whether the diver actually attached his explosive to the hull of the barge or set it on the bottom beneath the barge is unknown. What is known is that it worked--and probably would have in Norfolk had Alligator had the opportunity.**

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*Although rechristened the CSS Virginia, period reports--both Northern and Southern (even from Confederate naval officers)--routinely refer to the ironclad as the Merrimac[k].
**The lengths to which the North went to remedy the threat posed by the Merrimack can be judged by the fact that it accepted designs for three radically different ironclad vessels--Monitor, Galena, and New Ironsides--as well as Alligator, and, as a "just in case" last ditch effort, assembled a squadron of contracted civilian ships to ram the Confederate ironclad.

Raid on Gosport Navy Yard
 

Even before Merrimack was specifically targeted, Villeroi offered to make a general raid on Gosport Navy Yard in Norfolk. If Alligator could have succeeded against the rebel ironclad, she would have stood a good chance of sinking additional Confederate vessels in the navy yard.
 

Appomattox River Raid
(ref. Official Records)
 

This mission was not only a bad fit for a vessel such as Alligator, it was unfit for the Navy in general. Ultimately it was a failure and Commodore Rodgers was quite right to deny the submarine a place in the flotilla: it would have been lost or, perhaps worse, captured and employed against the Union fleet.

President Lincoln had ordered the bridge over the Appomattox destroyed; the Army could not do it, and the Navy had severe reservations about its ability to accomplish the mission along the shoal waters of the river. The fact that the use of a novel weapon such as Alligator was even countenanced is an indication of how desperately Secretary of the Navy Gideon Wells and (especially) Assistant Secretary Gus Fox wanted to take out the bridge. Following the failure of the naval surface expedition, Commander John Rodgers was replaced by Charles Wilkes. The new commander's plan to destroy the bridge relied upon ironclad canoes, built in the style he had seen in the Marianas Island when serving in the Pacific Squadron. Commodore Rodgers' prediction that they would not float proved wrong--but they did flip over. Wilkes claimed the Navy Yard in Washington had not followed his specifications. The Petersburg-Richmond railroad bridge was never attacked.* For an article on the abortive raid, click here.

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*Rear Admiral John Rodgers, 1812-1882, R. E. Johnson (USNI, Annapolis, 1967), pp. 215-216.
 

Drewry's Bluff
 

Alligator's assignment to the James River encompassed both the planned attack on the bridge over the Appomattox as well as the destruction of obstacles below Drewry's Bluff.  However inappropriate the submarine might have been on the attack against the railroad bridge, the underwater obstructions at Drewry's Bluff were an ideal target more suited to the abilities of  "salvage boat." McClellan's retreat from Richmond in the course of the Seven Days' Battles meant that the bluff was again beyond the reach of the Navy, which preferred not to be trapped along the narrow river without the support of the Union army.
 

Break the British Blockade
 

Most people do not realize how close we came to fighting World War One in 1862-1863. Even before the Trent Affair moved us close to open warfare with England, the support of Britain and France for the Southern Confederacy placed them in opposition to Lincoln's Union. Smarting from her recent loss to the French and British in the Crimean War, Russia let it be understood that it would ally itself with the North in any open conflict; in 1862, the Czar sent his Baltic and Pacific fleets on a "good will tour" of the western and eastern coasts of the United States--with secret orders to be ready to pounce on convoys bringing troops and supplies from Europe. The Navy's capture of New Orleans in April 1862 stayed the Europeans' hands and Gettysburg a year later ended once and for all the threat of a global war.

Would a squadron of a half-dozen Alligators, such as proposed by William Hirst in December 1861, have been an effective weapon against an Anglo-French blockade? The same problem posed by the depth of the water in an attack against Merrimack would have been faced off-shore: how to attack a floating vessel from the sea floor. Did Hirst already have an inkling of an alternative way to use Alligator, such as Sam Eakins seemed to be hinting at in his plan for the attack in Charleston harbor? (See below)

Charleston Harbor
 

The Union use of submarines in the harbor at Charleston, South Carolina was evidently quite common. In a war where any "secret" seemed to spread rather easily, the people involved with underwater warfare appear to be an exception. Recall that Sam Eakins was actually dismissed because he would not divulge his "other mode" of using Alligator when asked by Admiral Smith (see "Letters" #143). As per information related in Mark Ragan's "Civil War Submarines of the North and South," references to submarine operations in the harbor are plentiful. At one point, Admiral Dahlgren requests “3-4 submarines” to clear obstructions in Charleston harbor. His off-handed petition suggests that he recognized their use, assumed they were available, and expected them to be delivered. While the Union records make no mention of the delivery or use of any such vessels, a subsequent Confederate report indicates spotting a Union submarine being towed over the bar into the harbor and slipping under the surface – and out of the historical record. Only about two weeks before Admiral Dupont's ironclad attack, a reporter for the New York Times filed an article that recorded "a tremendous explosion" in the harbor that caused "a jarring sensation to the whole blockading squadron six miles off." He assumed it was the "premature explosion of some submarine torpedo." Undoubtedly--but had the underwater mine detonated accidentally or were Union submariners already at work clearing a path for the surface ships? There is no way to know.*

In removing obstructions that were anchored to the bottom--such as tethered mines--Alligator could have been very effective deploying a diver. This had been done quite reliably from Villeroi's boats for several years. But how could it have had any effect upon a floating log boom or chain suspended a few feet beneath the surface? Only an explosive tied to the links or line of logs would have had an effect. The fact that Eakins was willing to attempt the mission and sounds supremely confident in his ability to execute it using Alligator suggests that he understood better than we do how the submarine could be used. As per the longer article, this is entirely conjecture, but Sam might well have meant to make his attack via the upper hatch of the boat. If so, Alligator could have been very effective.

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What is also unknowable are what measures the Confederates took to defend against possible Union submarines, either active or passive. That they were aware of the presence of Northern boats is attested to in a letter written sometime in early April 1863 by General P.G.T. Beauregard, in charge of defending the city. In it, he specifically mentions being well aware of Alligator, although his statement that it has been seen must have been erroneous:

"The enemy . . .  are already in force in the Stono and the North Edisto, having seven monitors in the latter and their Alligator in the former (besides other vessels in both), so the trial of strength will soon commence. The War Department will now be able to determine whether this place or Wilmington is to be attacked." ( Army Official War Records, Series 111, pp. 227 -228)
 

Conclusion
 

Ultimately, Alligator never had the chance to succeed. Throughout her career, she suffered from bad timing and inappropriate missions. This is not to say that she would necessarily have been one hundred percent effective had she been properly deployed, but on those missions that fit her abilities (especially Drewry's Bluff), there is no reason to think she could  not have performed as well as her past demonstrated abilities suggested. Assignment such as Gosport Navy Yard, the Merrimack, and the British blockade are more problematical, and would have depended upon the depth of the water--or the ability of the submarine's "superintendent" to execute a "mode 2" attack.  Whether this manner of using the submarine is what Eakins had in mind for Charleston would also have greatly influenced the success of that mission.